Bump version to 3.3.0

# Conflicts:
#	pom.xml
#	src/main/java/org/qortal/controller/tradebot/TradeBot.java
#	src/main/java/org/qortal/crosschain/SupportedBlockchain.java
#	src/main/java/org/qortal/settings/Settings.java

WindowsInstaller/Qortal.aip

@@ -17,10 +17,10 @@
     <ROW Property="Manufacturer" Value="Qortal"/>
     <ROW Property="MsiLogging" MultiBuildValue="DefaultBuild:vp"/>
     <ROW Property="NTP_GOOD" Value="false"/>
-    <ROW Property="ProductCode" Value="1033:{0A40181D-6147-451B-ADA1-782F238DA2EF} 1049:{174FDC95-8017-43BC-A1F9-C96EFE1D4249} 2052:{4DF7B7E2-9CF2-4BE2-8CC4-AC2F2FFD3737} 2057:{0C9E4151-81C6-4726-AE80-E08DA8519DE4} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{8C9CFB9D-BC4C-4142-A5A5-5551BF3B9467} 1049:{4A5BDDD9-ED71-431A-A46F-D19E9DE17216} 2052:{0B9DCE00-BE23-434D-BD6A-1CFA6AB3CA43} 2057:{23D81967-556A-41B8-9981-A739E2820624} " Type="16"/>
     <ROW Property="ProductLanguage" Value="2057"/>
     <ROW Property="ProductName" Value="Qortal"/>
-    <ROW Property="ProductVersion" Value="3.2.4" Type="32"/>
+    <ROW Property="ProductVersion" Value="3.2.5" Type="32"/>
     <ROW Property="RECONFIG_NTP" Value="true"/>
     <ROW Property="REMOVE_BLOCKCHAIN" Value="YES" Type="4"/>
     <ROW Property="REPAIR_BLOCKCHAIN" Value="YES" Type="4"/>
@@ -212,7 +212,7 @@
     <ROW Component="ADDITIONAL_LICENSE_INFO_71" ComponentId="{12A3ADBE-BB7A-496C-8869-410681E6232F}" Directory_="jdk.zipfs_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_71" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_8" ComponentId="{D53AD95E-CF96-4999-80FC-5812277A7456}" Directory_="java.naming_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_8" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_9" ComponentId="{6B7EA9B0-5D17-47A8-B78C-FACE86D15E01}" Directory_="java.net.http_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_9" Type="0"/>
-    <ROW Component="AI_CustomARPName" ComponentId="{707946B1-D47E-4818-BD7B-60346E94940B}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
+    <ROW Component="AI_CustomARPName" ComponentId="{D5A1DC7D-914F-4425-8BA6-A1AE05D0F361}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
     <ROW Component="AI_ExePath" ComponentId="{3644948D-AE0B-41BB-9FAF-A79E70490A08}" Directory_="APPDIR" Attributes="260" KeyPath="AI_ExePath"/>
     <ROW Component="APPDIR" ComponentId="{680DFDDE-3FB4-47A5-8FF5-934F576C6F91}" Directory_="APPDIR" Attributes="0"/>
     <ROW Component="AccessBridgeCallbacks.h" ComponentId="{288055D1-1062-47A3-AA44-5601B4E38AED}" Directory_="bridge_Dir" Attributes="0" KeyPath="AccessBridgeCallbacks.h" Type="0"/>

pom.xml

@@ -3,11 +3,11 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>3.2.5</version>
+	<version>3.3.0</version>
 	<packaging>jar</packaging>
 	<properties>
 		<skipTests>true</skipTests>
-		<altcoinj.version>bf9fb80</altcoinj.version>
+		<altcoinj.version>6628cfd</altcoinj.version>
 		<bitcoinj.version>0.15.10</bitcoinj.version>
 		<bouncycastle.version>1.64</bouncycastle.version>
 		<build.timestamp>${maven.build.timestamp}</build.timestamp>
@@ -444,7 +444,7 @@
 		</dependency>
 		<!-- For Litecoin, etc. support, requires bitcoinj -->
 		<dependency>
-			<groupId>com.github.jjos2372</groupId>
+			<groupId>com.github.qortal</groupId>
 			<artifactId>altcoinj</artifactId>
 			<version>${altcoinj.version}</version>
 		</dependency>

src/main/java/org/qortal/api/model/crosschain/DigibyteSendRequest.java

@@ -0,0 +1,29 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class DigibyteSendRequest {
+
+	@Schema(description = "Digibyte BIP32 extended private key", example = "tprv___________________________________________________________________________________________________________")
+	public String xprv58;
+
+	@Schema(description = "Recipient's Digibyte address ('legacy' P2PKH only)", example = "1DigByteEaterAddressDontSendf59kuE")
+	public String receivingAddress;
+
+	@Schema(description = "Amount of DGB to send", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long digibyteAmount;
+
+	@Schema(description = "Transaction fee per byte (optional). Default is 0.00000100 DGB (100 sats) per byte", example = "0.00000100", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long feePerByte;
+
+	public DigibyteSendRequest() {
+	}
+
+}

src/main/java/org/qortal/api/model/crosschain/RavencoinSendRequest.java

@@ -0,0 +1,29 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class RavencoinSendRequest {
+
+	@Schema(description = "Ravencoin BIP32 extended private key", example = "tprv___________________________________________________________________________________________________________")
+	public String xprv58;
+
+	@Schema(description = "Recipient's Ravencoin address ('legacy' P2PKH only)", example = "1RvnCoinEaterAddressDontSendf59kuE")
+	public String receivingAddress;
+
+	@Schema(description = "Amount of RVN to send", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long ravencoinAmount;
+
+	@Schema(description = "Transaction fee per byte (optional). Default is 0.00000100 RVN (100 sats) per byte", example = "0.00000100", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long feePerByte;
+
+	public RavencoinSendRequest() {
+	}
+
+}

src/main/java/org/qortal/api/resource/AdminResource.java

@@ -381,6 +381,10 @@ public class AdminResource {
 			) @QueryParam("limit") Integer limit, @Parameter(
 				ref = "offset"
 			) @QueryParam("offset") Integer offset, @Parameter(
+				name = "tail",
+				description = "Fetch most recent log lines",
+				schema = @Schema(type = "boolean")
+			) @QueryParam("tail") Boolean tail, @Parameter(
 				ref = "reverse"
 			) @QueryParam("reverse") Boolean reverse) {
 		LoggerContext loggerContext = (LoggerContext) LogManager.getContext();
@@ -396,6 +400,13 @@ public class AdminResource {
 			if (reverse != null && reverse)
 				logLines = Lists.reverse(logLines);
 
+			// Tail mode - return the last X lines (where X = limit)
+			if (tail != null && tail) {
+				if (limit != null && limit > 0) {
+					offset = logLines.size() - limit;
+				}
+			}
+
 			// offset out of bounds?
 			if (offset != null && (offset < 0 || offset >= logLines.size()))
 				return "";
@@ -416,7 +427,7 @@ public class AdminResource {
 
 			limit = Math.min(limit, logLines.size());
 
-			logLines.subList(limit - 1, logLines.size()).clear();
+			logLines.subList(limit, logLines.size()).clear();
 
 			return String.join("\n", logLines);
 		} catch (IOException e) {

src/main/java/org/qortal/api/resource/CrossChainDigibyteResource.java

@@ -0,0 +1,177 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.HeaderParam;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.bitcoinj.core.Transaction;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.crosschain.DigibyteSendRequest;
+import org.qortal.crosschain.Digibyte;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.SimpleTransaction;
+
+@Path("/crosschain/dgb")
+@Tag(name = "Cross-Chain (Digibyte)")
+public class CrossChainDigibyteResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/walletbalance")
+	@Operation(
+		summary = "Returns DGB balance for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "balance (satoshis)"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getDigibyteWalletBalance(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		if (!digibyte.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			Long balance = digibyte.getWalletBalanceFromTransactions(key58);
+			if (balance == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return balance.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/wallettransactions")
+	@Operation(
+		summary = "Returns transactions for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(array = @ArraySchema( schema = @Schema( implementation = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public List<SimpleTransaction> getDigibyteWalletTransactions(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		if (!digibyte.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return digibyte.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/send")
+	@Operation(
+		summary = "Sends DGB from hierarchical, deterministic BIP32 wallet to specific address",
+		description = "Currently supports 'legacy' P2PKH Digibyte addresses and Native SegWit (P2WPKH) addresses. Supply BIP32 'm' private key in base58, starting with 'xprv' for mainnet, 'tprv' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = DigibyteSendRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "transaction hash"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String sendBitcoin(@HeaderParam(Security.API_KEY_HEADER) String apiKey, DigibyteSendRequest digibyteSendRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (digibyteSendRequest.digibyteAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (digibyteSendRequest.feePerByte != null && digibyteSendRequest.feePerByte <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		if (!digibyte.isValidAddress(digibyteSendRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (!digibyte.isValidDeterministicKey(digibyteSendRequest.xprv58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Transaction spendTransaction = digibyte.buildSpend(digibyteSendRequest.xprv58,
+				digibyteSendRequest.receivingAddress,
+				digibyteSendRequest.digibyteAmount,
+				digibyteSendRequest.feePerByte);
+
+		if (spendTransaction == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+		try {
+			digibyte.broadcastTransaction(spendTransaction);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+
+		return spendTransaction.getTxId().toString();
+	}
+
+}

src/main/java/org/qortal/api/resource/CrossChainRavencoinResource.java

@@ -0,0 +1,177 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.HeaderParam;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.bitcoinj.core.Transaction;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.crosschain.RavencoinSendRequest;
+import org.qortal.crosschain.Ravencoin;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.SimpleTransaction;
+
+@Path("/crosschain/rvn")
+@Tag(name = "Cross-Chain (Ravencoin)")
+public class CrossChainRavencoinResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/walletbalance")
+	@Operation(
+		summary = "Returns RVN balance for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "balance (satoshis)"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getRavencoinWalletBalance(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		if (!ravencoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			Long balance = ravencoin.getWalletBalanceFromTransactions(key58);
+			if (balance == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return balance.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/wallettransactions")
+	@Operation(
+		summary = "Returns transactions for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(array = @ArraySchema( schema = @Schema( implementation = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public List<SimpleTransaction> getRavencoinWalletTransactions(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		if (!ravencoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return ravencoin.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/send")
+	@Operation(
+		summary = "Sends RVN from hierarchical, deterministic BIP32 wallet to specific address",
+		description = "Currently only supports 'legacy' P2PKH Ravencoin addresses. Supply BIP32 'm' private key in base58, starting with 'xprv' for mainnet, 'tprv' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = RavencoinSendRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "transaction hash"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String sendBitcoin(@HeaderParam(Security.API_KEY_HEADER) String apiKey, RavencoinSendRequest ravencoinSendRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (ravencoinSendRequest.ravencoinAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (ravencoinSendRequest.feePerByte != null && ravencoinSendRequest.feePerByte <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		if (!ravencoin.isValidAddress(ravencoinSendRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (!ravencoin.isValidDeterministicKey(ravencoinSendRequest.xprv58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Transaction spendTransaction = ravencoin.buildSpend(ravencoinSendRequest.xprv58,
+				ravencoinSendRequest.receivingAddress,
+				ravencoinSendRequest.ravencoinAmount,
+				ravencoinSendRequest.feePerByte);
+
+		if (spendTransaction == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+		try {
+			ravencoin.broadcastTransaction(spendTransaction);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+
+		return spendTransaction.getTxId().toString();
+	}
+
+}

src/main/java/org/qortal/api/resource/PeersResource.java

@@ -20,6 +20,11 @@ import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.core.config.Configuration;
+import org.apache.logging.log4j.core.config.LoggerConfig;
+import org.apache.logging.log4j.core.LoggerContext;
 import org.qortal.api.*;
 import org.qortal.api.model.ConnectedPeer;
 import org.qortal.api.model.PeersSummary;
@@ -127,9 +132,29 @@ public class PeersResource {
 		}
 	)
 	@SecurityRequirement(name = "apiKey")
-	public ExecuteProduceConsume.StatsSnapshot getEngineStats(@HeaderParam(Security.API_KEY_HEADER) String apiKey) {
+	public ExecuteProduceConsume.StatsSnapshot getEngineStats(@HeaderParam(Security.API_KEY_HEADER) String apiKey, @QueryParam("newLoggingLevel") Level newLoggingLevel) {
 		Security.checkApiCallAllowed(request);
 
+		if (newLoggingLevel != null) {
+			final LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
+			final Configuration config = ctx.getConfiguration();
+
+			String epcClassName = "org.qortal.network.Network.NetworkProcessor";
+			LoggerConfig loggerConfig = config.getLoggerConfig(epcClassName);
+			LoggerConfig specificConfig = loggerConfig;
+
+			// We need a specific configuration for this logger,
+			// otherwise we would change the level of all other loggers
+			// having the original configuration as parent as well
+			if (!loggerConfig.getName().equals(epcClassName)) {
+				specificConfig = new LoggerConfig(epcClassName, newLoggingLevel, true);
+				specificConfig.setParent(loggerConfig);
+				config.addLogger(epcClassName, specificConfig);
+			}
+			specificConfig.setLevel(newLoggingLevel);
+			ctx.updateLoggers();
+		}
+
 		return Network.getInstance().getStatsSnapshot();
 	}
 

src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java

@@ -93,10 +93,12 @@ public class ArbitraryDataFile {
         File outputFile = outputFilePath.toFile();
         try (FileOutputStream outputStream = new FileOutputStream(outputFile)) {
             outputStream.write(fileContent);
+            outputStream.close();
             this.filePath = outputFilePath;
             // Verify hash
-            if (!this.hash58.equals(this.digest58())) {
-                LOGGER.error("Hash {} does not match file digest {} for signature: {}", this.hash58, this.digest58(), Base58.encode(signature));
+            String digest58 = this.digest58();
+            if (!this.hash58.equals(digest58)) {
+                LOGGER.error("Hash {} does not match file digest {} for signature: {}", this.hash58, digest58, Base58.encode(signature));
                 this.delete();
                 throw new DataException("Data file digest validation failed");
             }

src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java

@@ -120,7 +120,7 @@ public class ArbitraryDataRenderer {
                 byte[] data = Files.readAllBytes(Paths.get(filePath)); // TODO: limit file size that can be read into memory
                 HTMLParser htmlParser = new HTMLParser(resourceId, inPath, prefix, usePrefix, data);
                 htmlParser.addAdditionalHeaderTags();
-                response.addHeader("Content-Security-Policy", "default-src 'self' 'unsafe-inline' 'unsafe-eval'; media-src 'self' blob:");
+                response.addHeader("Content-Security-Policy", "default-src 'self' 'unsafe-inline' 'unsafe-eval'; media-src 'self' blob:; img-src 'self' data: blob:;");
                 response.setContentType(context.getMimeType(filename));
                 response.setContentLength(htmlParser.getData().length);
                 response.getOutputStream().write(htmlParser.getData());

src/main/java/org/qortal/controller/Controller.java

@@ -58,6 +58,7 @@ import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
 import org.qortal.settings.Settings;
 import org.qortal.transaction.Transaction;
 import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.transform.TransformationException;
 import org.qortal.utils.*;
 
 public class Controller extends Thread {
@@ -1218,7 +1219,7 @@ public class Controller extends Thread {
 			this.stats.getBlockMessageStats.cacheHits.incrementAndGet();
 
 			// We need to duplicate it to prevent multiple threads setting ID on the same message
-			CachedBlockMessage clonedBlockMessage = cachedBlockMessage.cloneWithNewId(message.getId());
+			CachedBlockMessage clonedBlockMessage = Message.cloneWithNewId(cachedBlockMessage, message.getId());
 
 			if (!peer.sendMessage(clonedBlockMessage))
 				peer.disconnect("failed to send block");
@@ -1277,7 +1278,6 @@ public class Controller extends Thread {
 			CachedBlockMessage blockMessage = new CachedBlockMessage(block);
 			blockMessage.setId(message.getId());
 
-			// This call also causes the other needed data to be pulled in from repository
 			if (!peer.sendMessage(blockMessage)) {
 				peer.disconnect("failed to send block");
 				// Don't fall-through to caching because failure to send might be from failure to build message
@@ -1291,7 +1291,9 @@ public class Controller extends Thread {
 				this.blockMessageCache.put(ByteArray.wrap(blockData.getSignature()), blockMessage);
 			}
 		} catch (DataException e) {
-			LOGGER.error(String.format("Repository issue while send block %s to peer %s", Base58.encode(signature), peer), e);
+			LOGGER.error(String.format("Repository issue while sending block %s to peer %s", Base58.encode(signature), peer), e);
+		} catch (TransformationException e) {
+			LOGGER.error(String.format("Serialization issue while sending block %s to peer %s", Base58.encode(signature), peer), e);
 		}
 	}
 

src/main/java/org/qortal/controller/Synchronizer.java

@@ -33,7 +33,7 @@ import org.qortal.network.message.GetBlockSummariesMessage;
 import org.qortal.network.message.GetSignaturesV2Message;
 import org.qortal.network.message.Message;
 import org.qortal.network.message.SignaturesMessage;
-import org.qortal.network.message.Message.MessageType;
+import org.qortal.network.message.MessageType;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;

src/main/java/org/qortal/controller/TransactionImporter.java

@@ -12,6 +12,7 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.Transaction;
+import org.qortal.transform.TransformationException;
 import org.qortal.utils.Base58;
 import org.qortal.utils.NTP;
 
@@ -289,7 +290,9 @@ public class TransactionImporter extends Thread {
             if (!peer.sendMessage(transactionMessage))
                 peer.disconnect("failed to send transaction");
         } catch (DataException e) {
-            LOGGER.error(String.format("Repository issue while send transaction %s to peer %s", Base58.encode(signature), peer), e);
+            LOGGER.error(String.format("Repository issue while sending transaction %s to peer %s", Base58.encode(signature), peer), e);
+        } catch (TransformationException e) {
+            LOGGER.error(String.format("Serialization issue while sending transaction %s to peer %s", Base58.encode(signature), peer), e);
         }
     }
 

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileListManager.java

@@ -511,18 +511,23 @@ public class ArbitraryDataFileListManager {
 
                     // Bump requestHops if it exists
                     if (requestHops != null) {
-                        arbitraryDataFileListMessage.setRequestHops(++requestHops);
+                        requestHops++;
                     }
 
+                    ArbitraryDataFileListMessage forwardArbitraryDataFileListMessage;
+
                     // Remove optional parameters if the requesting peer doesn't support it yet
                     // A message with less statistical data is better than no message at all
                     if (!requestingPeer.isAtLeastVersion(MIN_PEER_VERSION_FOR_FILE_LIST_STATS)) {
-                        arbitraryDataFileListMessage.removeOptionalStats();
+                        forwardArbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes);
+                    } else {
+                        forwardArbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes, requestTime, requestHops,
+                                arbitraryDataFileListMessage.getPeerAddress(), arbitraryDataFileListMessage.isRelayPossible());
                     }
 
                     // Forward to requesting peer
                     LOGGER.debug("Forwarding file list with {} hashes to requesting peer: {}", hashes.size(), requestingPeer);
-                    if (!requestingPeer.sendMessage(arbitraryDataFileListMessage)) {
+                    if (!requestingPeer.sendMessage(forwardArbitraryDataFileListMessage)) {
                         requestingPeer.disconnect("failed to forward arbitrary data file list");
                     }
                 }
@@ -639,16 +644,19 @@ public class ArbitraryDataFileListManager {
             }
 
             String ourAddress = Network.getInstance().getOurExternalIpAddressAndPort();
-            ArbitraryDataFileListMessage arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature,
-                    hashes, NTP.getTime(), 0, ourAddress, true);
-            arbitraryDataFileListMessage.setId(message.getId());
+            ArbitraryDataFileListMessage arbitraryDataFileListMessage;
 
             // Remove optional parameters if the requesting peer doesn't support it yet
             // A message with less statistical data is better than no message at all
             if (!peer.isAtLeastVersion(MIN_PEER_VERSION_FOR_FILE_LIST_STATS)) {
-                arbitraryDataFileListMessage.removeOptionalStats();
+                arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes);
+            } else {
+                arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature,
+                        hashes, NTP.getTime(), 0, ourAddress, true);
             }
 
+            arbitraryDataFileListMessage.setId(message.getId());
+
             if (!peer.sendMessage(arbitraryDataFileListMessage)) {
                 LOGGER.debug("Couldn't send list of hashes");
                 peer.disconnect("failed to send list of hashes");
@@ -670,8 +678,7 @@ public class ArbitraryDataFileListManager {
             // In relay mode - so ask our other peers if they have it
 
             long requestTime = getArbitraryDataFileListMessage.getRequestTime();
-            int requestHops = getArbitraryDataFileListMessage.getRequestHops();
-            getArbitraryDataFileListMessage.setRequestHops(++requestHops);
+            int requestHops = getArbitraryDataFileListMessage.getRequestHops() + 1;
             long totalRequestTime = now - requestTime;
 
             if (totalRequestTime < RELAY_REQUEST_MAX_DURATION) {
@@ -679,11 +686,13 @@ public class ArbitraryDataFileListManager {
                 if (requestHops < RELAY_REQUEST_MAX_HOPS) {
                     // Relay request hasn't reached the maximum number of hops yet, so can be rebroadcast
 
+                    Message relayGetArbitraryDataFileListMessage = new GetArbitraryDataFileListMessage(signature, hashes, requestTime, requestHops, requestingPeer);
+
                     LOGGER.debug("Rebroadcasting hash list request from peer {} for signature {} to our other peers... totalRequestTime: {}, requestHops: {}", peer, Base58.encode(signature), totalRequestTime, requestHops);
                     Network.getInstance().broadcast(
                             broadcastPeer -> broadcastPeer == peer ||
                                     Objects.equals(broadcastPeer.getPeerData().getAddress().getHost(), peer.getPeerData().getAddress().getHost())
-                                    ? null : getArbitraryDataFileListMessage);
+                                    ? null : relayGetArbitraryDataFileListMessage);
 
                 }
                 else {

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java

@@ -7,7 +7,6 @@ import org.qortal.controller.Controller;
 import org.qortal.data.arbitrary.ArbitraryDirectConnectionInfo;
 import org.qortal.data.arbitrary.ArbitraryFileListResponseInfo;
 import org.qortal.data.arbitrary.ArbitraryRelayInfo;
-import org.qortal.data.network.ArbitraryPeerData;
 import org.qortal.data.network.PeerData;
 import org.qortal.data.transaction.ArbitraryTransactionData;
 import org.qortal.network.Network;
@@ -187,7 +186,7 @@ public class ArbitraryDataFileManager extends Thread {
         ArbitraryDataFile existingFile = ArbitraryDataFile.fromHash(hash, signature);
         boolean fileAlreadyExists = existingFile.exists();
         String hash58 = Base58.encode(hash);
-        Message message = null;
+        ArbitraryDataFileMessage arbitraryDataFileMessage;
 
         // Fetch the file if it doesn't exist locally
         if (!fileAlreadyExists) {
@@ -195,10 +194,11 @@ public class ArbitraryDataFileManager extends Thread {
             arbitraryDataFileRequests.put(hash58, NTP.getTime());
             Message getArbitraryDataFileMessage = new GetArbitraryDataFileMessage(signature, hash);
 
+            Message response = null;
             try {
-                message = peer.getResponseWithTimeout(getArbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT);
+                response = peer.getResponseWithTimeout(getArbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT);
             } catch (InterruptedException e) {
-                // Will return below due to null message
+                // Will return below due to null response
             }
             arbitraryDataFileRequests.remove(hash58);
             LOGGER.trace(String.format("Removed hash %.8s from arbitraryDataFileRequests", hash58));
@@ -206,22 +206,24 @@ public class ArbitraryDataFileManager extends Thread {
             // We may need to remove the file list request, if we have all the files for this transaction
             this.handleFileListRequests(signature);
 
-            if (message == null) {
-                LOGGER.debug("Received null message from peer {}", peer);
+            if (response == null) {
+                LOGGER.debug("Received null response from peer {}", peer);
                 return null;
             }
-            if (message.getType() != Message.MessageType.ARBITRARY_DATA_FILE) {
-                LOGGER.debug("Received message with invalid type: {} from peer {}", message.getType(), peer);
+            if (response.getType() != MessageType.ARBITRARY_DATA_FILE) {
+                LOGGER.debug("Received response with invalid type: {} from peer {}", response.getType(), peer);
                 return null;
             }
-        }
-        else {
+
+            ArbitraryDataFileMessage peersArbitraryDataFileMessage = (ArbitraryDataFileMessage) response;
+            arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, peersArbitraryDataFileMessage.getArbitraryDataFile());
+        } else {
             LOGGER.debug(String.format("File hash %s already exists, so skipping the request", hash58));
+            arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, existingFile);
         }
-        ArbitraryDataFileMessage arbitraryDataFileMessage = (ArbitraryDataFileMessage) message;
 
         // We might want to forward the request to the peer that originally requested it
-        this.handleArbitraryDataFileForwarding(requestingPeer, message, originalMessage);
+        this.handleArbitraryDataFileForwarding(requestingPeer, arbitraryDataFileMessage, originalMessage);
 
         boolean isRelayRequest = (requestingPeer != null);
         if (isRelayRequest) {

src/main/java/org/qortal/controller/arbitrary/ArbitraryMetadataManager.java

@@ -338,9 +338,11 @@ public class ArbitraryMetadataManager {
                 Peer requestingPeer = request.getB();
                 if (requestingPeer != null) {
 
+                    ArbitraryMetadataMessage forwardArbitraryMetadataMessage = new ArbitraryMetadataMessage(signature, arbitraryMetadataMessage.getArbitraryMetadataFile());
+
                     // Forward to requesting peer
                     LOGGER.debug("Forwarding metadata to requesting peer: {}", requestingPeer);
-                    if (!requestingPeer.sendMessage(arbitraryMetadataMessage)) {
+                    if (!requestingPeer.sendMessage(forwardArbitraryMetadataMessage)) {
                         requestingPeer.disconnect("failed to forward arbitrary metadata");
                     }
                 }
@@ -423,8 +425,7 @@ public class ArbitraryMetadataManager {
             // In relay mode - so ask our other peers if they have it
 
             long requestTime = getArbitraryMetadataMessage.getRequestTime();
-            int requestHops = getArbitraryMetadataMessage.getRequestHops();
-            getArbitraryMetadataMessage.setRequestHops(++requestHops);
+            int requestHops = getArbitraryMetadataMessage.getRequestHops() + 1;
             long totalRequestTime = now - requestTime;
 
             if (totalRequestTime < RELAY_REQUEST_MAX_DURATION) {
@@ -432,11 +433,13 @@ public class ArbitraryMetadataManager {
                 if (requestHops < RELAY_REQUEST_MAX_HOPS) {
                     // Relay request hasn't reached the maximum number of hops yet, so can be rebroadcast
 
+                    Message relayGetArbitraryMetadataMessage = new GetArbitraryMetadataMessage(signature, requestTime, requestHops);
+
                     LOGGER.debug("Rebroadcasting metadata request from peer {} for signature {} to our other peers... totalRequestTime: {}, requestHops: {}", peer, Base58.encode(signature), totalRequestTime, requestHops);
                     Network.getInstance().broadcast(
                             broadcastPeer -> broadcastPeer == peer ||
                                     Objects.equals(broadcastPeer.getPeerData().getAddress().getHost(), peer.getPeerData().getAddress().getHost())
-                                    ? null : getArbitraryMetadataMessage);
+                                    ? null : relayGetArbitraryMetadataMessage);
 
                 }
                 else {

src/main/java/org/qortal/controller/repository/NamesDatabaseIntegrityCheck.java

@@ -107,7 +107,7 @@ public class NamesDatabaseIntegrityCheck {
                     BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) currentTransaction;
                     Name nameObj = new Name(repository, buyNameTransactionData.getName());
                     if (nameObj != null && nameObj.getNameData() != null) {
-                        nameObj.buy(buyNameTransactionData);
+                        nameObj.buy(buyNameTransactionData, false);
                         modificationCount++;
                         LOGGER.trace("Processed BUY_NAME transaction for name {}", name);
                     }

src/main/java/org/qortal/controller/tradebot/DigibyteACCTv3TradeBot.java

@@ -0,0 +1,885 @@
+package org.qortal.controller.tradebot;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.*;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.*;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+/**
+ * Performing cross-chain trading steps on behalf of user.
+ * <p>
+ * We deal with three different independent state-spaces here:
+ * <ul>
+ * 	<li>Qortal blockchain</li>
+ * 	<li>Foreign blockchain</li>
+ * 	<li>Trade-bot entries</li>
+ * </ul>
+ */
+public class DigibyteACCTv3TradeBot implements AcctTradeBot {
+
+	private static final Logger LOGGER = LogManager.getLogger(DigibyteACCTv3TradeBot.class);
+
+	public enum State implements TradeBot.StateNameAndValueSupplier {
+		BOB_WAITING_FOR_AT_CONFIRM(10, false, false),
+		BOB_WAITING_FOR_MESSAGE(15, true, true),
+		BOB_WAITING_FOR_AT_REDEEM(25, true, true),
+		BOB_DONE(30, false, false),
+		BOB_REFUNDED(35, false, false),
+
+		ALICE_WAITING_FOR_AT_LOCK(85, true, true),
+		ALICE_DONE(95, false, false),
+		ALICE_REFUNDING_A(105, true, true),
+		ALICE_REFUNDED(110, false, false);
+
+		private static final Map<Integer, State> map = stream(State.values()).collect(toMap(state -> state.value, state -> state));
+
+		public final int value;
+		public final boolean requiresAtData;
+		public final boolean requiresTradeData;
+
+		State(int value, boolean requiresAtData, boolean requiresTradeData) {
+			this.value = value;
+			this.requiresAtData = requiresAtData;
+			this.requiresTradeData = requiresTradeData;
+		}
+
+		public static State valueOf(int value) {
+			return map.get(value);
+		}
+
+		@Override
+		public String getState() {
+			return this.name();
+		}
+
+		@Override
+		public int getStateValue() {
+			return this.value;
+		}
+	}
+
+	/** Maximum time Bob waits for his AT creation transaction to be confirmed into a block. (milliseconds) */
+	private static final long MAX_AT_CONFIRMATION_PERIOD = 24 * 60 * 60 * 1000L; // ms
+
+	private static DigibyteACCTv3TradeBot instance;
+
+	private final List<String> endStates = Arrays.asList(State.BOB_DONE, State.BOB_REFUNDED, State.ALICE_DONE, State.ALICE_REFUNDING_A, State.ALICE_REFUNDED).stream()
+			.map(State::name)
+			.collect(Collectors.toUnmodifiableList());
+
+	private DigibyteACCTv3TradeBot() {
+	}
+
+	public static synchronized DigibyteACCTv3TradeBot getInstance() {
+		if (instance == null)
+			instance = new DigibyteACCTv3TradeBot();
+
+		return instance;
+	}
+
+	@Override
+	public List<String> getEndStates() {
+		return this.endStates;
+	}
+
+	/**
+	 * Creates a new trade-bot entry from the "Bob" viewpoint, i.e. OFFERing QORT in exchange for DGB.
+	 * <p>
+	 * Generates:
+	 * <ul>
+	 * 	<li>new 'trade' private key</li>
+	 * </ul>
+	 * Derives:
+	 * <ul>
+	 * 	<li>'native' (as in Qortal) public key, public key hash, address (starting with Q)</li>
+	 * 	<li>'foreign' (as in Digibyte) public key, public key hash</li>
+	 * </ul>
+	 * A Qortal AT is then constructed including the following as constants in the 'data segment':
+	 * <ul>
+	 * 	<li>'native'/Qortal 'trade' address - used as a MESSAGE contact</li>
+	 * 	<li>'foreign'/Digibyte public key hash - used by Alice's P2SH scripts to allow redeem</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>DGB amount expected in return by Bob (from Alice)</li>
+	 * 	<li>trading timeout, in case things go wrong and everyone needs to refund</li>
+	 * </ul>
+	 * Returns a DEPLOY_AT transaction that needs to be signed and broadcast to the Qortal network.
+	 * <p>
+	 * Trade-bot will wait for Bob's AT to be deployed before taking next step.
+	 * <p>
+	 * @param repository
+	 * @param tradeBotCreateRequest
+	 * @return raw, unsigned DEPLOY_AT transaction
+	 * @throws DataException
+	 */
+	public byte[] createTrade(Repository repository, TradeBotCreateRequest tradeBotCreateRequest) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+
+		// Convert Digibyte receiving address into public key hash (we only support P2PKH at this time)
+		Address digibyteReceivingAddress;
+		try {
+			digibyteReceivingAddress = Address.fromString(Digibyte.getInstance().getNetworkParameters(), tradeBotCreateRequest.receivingAddress);
+		} catch (AddressFormatException e) {
+			throw new DataException("Unsupported Digibyte receiving address: " + tradeBotCreateRequest.receivingAddress);
+		}
+		if (digibyteReceivingAddress.getOutputScriptType() != ScriptType.P2PKH)
+			throw new DataException("Unsupported Digibyte receiving address: " + tradeBotCreateRequest.receivingAddress);
+
+		byte[] digibyteReceivingAccountInfo = digibyteReceivingAddress.getHash();
+
+		PublicKeyAccount creator = new PublicKeyAccount(repository, tradeBotCreateRequest.creatorPublicKey);
+
+		// Deploy AT
+		long timestamp = NTP.getTime();
+		byte[] reference = creator.getLastReference();
+		long fee = 0L;
+		byte[] signature = null;
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, creator.getPublicKey(), fee, signature);
+
+		String name = "QORT/DGB ACCT";
+		String description = "QORT/DGB cross-chain trade";
+		String aTType = "ACCT";
+		String tags = "ACCT QORT DGB";
+		byte[] creationBytes = DigibyteACCTv3.buildQortalAT(tradeNativeAddress, tradeForeignPublicKeyHash, tradeBotCreateRequest.qortAmount,
+				tradeBotCreateRequest.foreignAmount, tradeBotCreateRequest.tradeTimeout);
+		long amount = tradeBotCreateRequest.fundingQortAmount;
+
+		DeployAtTransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, aTType, tags, creationBytes, amount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		DeployAtTransaction.ensureATAddress(deployAtTransactionData);
+		String atAddress = deployAtTransactionData.getAtAddress();
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, DigibyteACCTv3.NAME,
+				State.BOB_WAITING_FOR_AT_CONFIRM.name(), State.BOB_WAITING_FOR_AT_CONFIRM.value,
+				creator.getAddress(), atAddress, timestamp, tradeBotCreateRequest.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				null, null,
+				SupportedBlockchain.DIGIBYTE.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				tradeBotCreateRequest.foreignAmount, null, null, null, digibyteReceivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Built AT %s. Waiting for deployment", atAddress));
+
+		// Attempt to backup the trade bot data
+		TradeBot.backupTradeBotData(repository, null);
+
+		// Return to user for signing and broadcast as we don't have their Qortal private key
+		try {
+			return DeployAtTransactionTransformer.toBytes(deployAtTransactionData);
+		} catch (TransformationException e) {
+			throw new DataException("Failed to transform DEPLOY_AT transaction?", e);
+		}
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint, i.e. matching DGB to an existing offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a Digibyte wallet via <tt>xprv58</tt>.
+	 * <p>
+	 * The <tt>crossChainTradeData</tt> contains the current trade offer state
+	 * as extracted from the AT's data segment.
+	 * <p>
+	 * Access to a funded wallet is via a Digibyte BIP32 hierarchical deterministic key,
+	 * passed via <tt>xprv58</tt>.
+	 * <b>This key will be stored in your node's database</b>
+	 * to allow trade-bot to create/fund the necessary P2SH transactions!
+	 * However, due to the nature of BIP32 keys, it is possible to give the trade-bot
+	 * only a subset of wallet access (see BIP32 for more details).
+	 * <p>
+	 * As an example, the xprv58 can be extract from a <i>legacy, password-less</i>
+	 * Electrum wallet by going to the console tab and entering:<br>
+	 * <tt>wallet.keystore.xprv</tt><br>
+	 * which should result in a base58 string starting with either 'xprv' (for Digibyte main-net)
+	 * or 'tprv' for (Digibyte test-net).
+	 * <p>
+	 * It is envisaged that the value in <tt>xprv58</tt> will actually come from a Qortal-UI-managed wallet.
+	 * <p>
+	 * If sufficient funds are available, <b>this method will actually fund the P2SH-A</b>
+	 * with the Digibyte amount expected by 'Bob'.
+	 * <p>
+	 * If the Digibyte transaction is successfully broadcast to the network then
+	 * we also send a MESSAGE to Bob's trade-bot to let them know.
+	 * <p>
+	 * The trade-bot entry is saved to the repository and the cross-chain trading process commences.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeData chosen trade OFFER that Alice wants to match
+	 * @param xprv58 funded wallet xprv in base58
+	 * @return true if P2SH-A funding transaction successfully broadcast to Digibyte network, false otherwise
+	 * @throws DataException
+	 */
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct, CrossChainTradeData crossChainTradeData, String xprv58, String receivingAddress) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+		byte[] secretA = TradeBot.generateSecret();
+		byte[] hashOfSecretA = Crypto.hash160(secretA);
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+		byte[] receivingPublicKeyHash = Base58.decode(receivingAddress); // Actually the whole address, not just PKH
+
+		// We need to generate lockTime-A: add tradeTimeout to now
+		long now = NTP.getTime();
+		int lockTimeA = crossChainTradeData.tradeTimeout * 60 + (int) (now / 1000L);
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, DigibyteACCTv3.NAME,
+				State.ALICE_WAITING_FOR_AT_LOCK.name(), State.ALICE_WAITING_FOR_AT_LOCK.value,
+				receivingAddress, crossChainTradeData.qortalAtAddress, now, crossChainTradeData.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				secretA, hashOfSecretA,
+				SupportedBlockchain.DIGIBYTE.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				crossChainTradeData.expectedForeignAmount, xprv58, null, lockTimeA, receivingPublicKeyHash);
+
+		// Attempt to backup the trade bot data
+		// Include tradeBotData as an additional parameter, since it's not in the repository yet
+		TradeBot.backupTradeBotData(repository, Arrays.asList(tradeBotData));
+
+		// Check we have enough funds via xprv58 to fund P2SH to cover expectedForeignAmount
+		long p2shFee;
+		try {
+			p2shFee = Digibyte.getInstance().getP2shFee(now);
+		} catch (ForeignBlockchainException e) {
+			LOGGER.debug("Couldn't estimate Digibyte fees?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		// Do not include fee for funding transaction as this is covered by buildSpend()
+		long amountA = crossChainTradeData.expectedForeignAmount + p2shFee /*redeeming/refunding P2SH-A*/;
+
+		// P2SH-A to be funded
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(tradeForeignPublicKeyHash, lockTimeA, crossChainTradeData.creatorForeignPKH, hashOfSecretA);
+		String p2shAddress = Digibyte.getInstance().deriveP2shAddress(redeemScriptBytes);
+
+		// Build transaction for funding P2SH-A
+		Transaction p2shFundingTransaction = Digibyte.getInstance().buildSpend(tradeBotData.getForeignKey(), p2shAddress, amountA);
+		if (p2shFundingTransaction == null) {
+			LOGGER.debug("Unable to build P2SH-A funding transaction - lack of funds?");
+			return ResponseResult.BALANCE_ISSUE;
+		}
+
+		try {
+			Digibyte.getInstance().broadcastTransaction(p2shFundingTransaction);
+		} catch (ForeignBlockchainException e) {
+			// We couldn't fund P2SH-A at this time
+			LOGGER.debug("Couldn't broadcast P2SH-A funding transaction?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Attempt to send MESSAGE to Bob's Qortal trade address
+		byte[] messageData = DigibyteACCTv3.buildOfferMessage(tradeBotData.getTradeForeignPublicKeyHash(), tradeBotData.getHashOfSecret(), tradeBotData.getLockTimeA());
+		String messageRecipient = crossChainTradeData.qortalCreatorTradeAddress;
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+				return ResponseResult.NETWORK_ISSUE;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
+
+		return ResponseResult.OK;
+	}
+
+	@Override
+	public boolean canDelete(Repository repository, TradeBotData tradeBotData) throws DataException {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null)
+			return true;
+
+		// If the AT doesn't exist then we might as well let the user tidy up
+		if (!repository.getATRepository().exists(tradeBotData.getAtAddress()))
+			return true;
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+			case ALICE_DONE:
+			case BOB_DONE:
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+			case ALICE_REFUNDING_A:
+				return true;
+
+			default:
+				return false;
+		}
+	}
+
+	@Override
+	public void progress(Repository repository, TradeBotData tradeBotData) throws DataException, ForeignBlockchainException {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null) {
+			LOGGER.info(() -> String.format("Trade-bot entry for AT %s has invalid state?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		ATData atData = null;
+		CrossChainTradeData tradeData = null;
+
+		if (tradeBotState.requiresAtData) {
+			// Attempt to fetch AT data
+			atData = repository.getATRepository().fromATAddress(tradeBotData.getAtAddress());
+			if (atData == null) {
+				LOGGER.debug(() -> String.format("Unable to fetch trade AT %s from repository", tradeBotData.getAtAddress()));
+				return;
+			}
+
+			if (tradeBotState.requiresTradeData) {
+				tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+				if (tradeData == null) {
+					LOGGER.warn(() -> String.format("Unable to fetch ACCT trade data for AT %s from repository", tradeBotData.getAtAddress()));
+					return;
+				}
+			}
+		}
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+				handleBobWaitingForAtConfirm(repository, tradeBotData);
+				break;
+
+			case BOB_WAITING_FOR_MESSAGE:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForMessage(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_WAITING_FOR_AT_LOCK:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceWaitingForAtLock(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case BOB_WAITING_FOR_AT_REDEEM:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForAtRedeem(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_DONE:
+			case BOB_DONE:
+				break;
+
+			case ALICE_REFUNDING_A:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceRefundingP2shA(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+				break;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to deploy.
+	 * <p>
+	 * If AT is deployed, then trade-bot's next step is to wait for MESSAGE from Alice.
+	 */
+	private void handleBobWaitingForAtConfirm(Repository repository, TradeBotData tradeBotData) throws DataException {
+		if (!repository.getATRepository().exists(tradeBotData.getAtAddress())) {
+			if (NTP.getTime() - tradeBotData.getTimestamp() <= MAX_AT_CONFIRMATION_PERIOD)
+				return;
+
+			// We've waited ages for AT to be confirmed into a block but something has gone awry.
+			// After this long we assume transaction loss so give up with trade-bot entry too.
+			tradeBotData.setState(State.BOB_REFUNDED.name());
+			tradeBotData.setStateValue(State.BOB_REFUNDED.value);
+			tradeBotData.setTimestamp(NTP.getTime());
+			// We delete trade-bot entry here instead of saving, hence not using updateTradeBotState()
+			repository.getCrossChainRepository().delete(tradeBotData.getTradePrivateKey());
+			repository.saveChanges();
+
+			LOGGER.info(() -> String.format("AT %s never confirmed. Giving up on trade", tradeBotData.getAtAddress()));
+			TradeBot.notifyStateChange(tradeBotData);
+			return;
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_MESSAGE,
+				() -> String.format("AT %s confirmed ready. Waiting for trade message", tradeBotData.getAtAddress()));
+	}
+
+	/**
+	 * Trade-bot is waiting for MESSAGE from Alice's trade-bot, containing Alice's trade info.
+	 * <p>
+	 * It's possible Bob has cancelling his trade offer, receiving an automatic QORT refund,
+	 * in which case trade-bot is done with this specific trade and finalizes on refunded state.
+	 * <p>
+	 * Assuming trade is still on offer, trade-bot checks the contents of MESSAGE from Alice's trade-bot.
+	 * <p>
+	 * Details from Alice are used to derive P2SH-A address and this is checked for funding balance.
+	 * <p>
+	 * Assuming P2SH-A has at least expected Digibyte balance,
+	 * Bob's trade-bot constructs a zero-fee, PoW MESSAGE to send to Bob's AT with more trade details.
+	 * <p>
+	 * On processing this MESSAGE, Bob's AT should switch into 'TRADE' mode and only trade with Alice.
+	 * <p>
+	 * Trade-bot's next step is to wait for Alice to redeem the AT, which will allow Bob to
+	 * extract secret-A needed to redeem Alice's P2SH.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForMessage(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// If AT has finished then Bob likely cancelled his trade offer
+		if (atData.getIsFinished()) {
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s cancelled - trading aborted", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		String address = tradeBotData.getTradeNativeAddress();
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, address, null, null, null);
+
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			if (messageTransactionData.isText())
+				continue;
+
+			// We're expecting: HASH160(secret-A), Alice's Digibyte pubkeyhash and lockTime-A
+			byte[] messageData = messageTransactionData.getData();
+			DigibyteACCTv3.OfferMessageData offerMessageData = DigibyteACCTv3.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				continue;
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerDigibytePKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+			long messageTimestamp = messageTransactionData.getTimestamp();
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(messageTimestamp, lockTimeA);
+
+			// Determine P2SH-A address and confirm funded
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(aliceForeignPublicKeyHash, lockTimeA, tradeBotData.getTradeForeignPublicKeyHash(), hashOfSecretA);
+			String p2shAddressA = digibyte.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Digibyte.getInstance().getP2shFee(feeTimestamp);
+			final long minimumAmountA = tradeBotData.getForeignAmount() + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(digibyte.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+					// There might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// We've already redeemed this?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade complete", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					// This P2SH-A is burnt, but there might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case FUNDED:
+					// Fall-through out of switch...
+					break;
+			}
+
+			// Good to go - send MESSAGE to AT
+
+			String aliceNativeAddress = Crypto.toAddress(messageTransactionData.getCreatorPublicKey());
+
+			// Build outgoing message, padding each part to 32 bytes to make it easier for AT to consume
+			byte[] outgoingMessageData = DigibyteACCTv3.buildTradeMessage(aliceNativeAddress, aliceForeignPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			String messageRecipient = tradeBotData.getAtAddress();
+
+			boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, outgoingMessageData);
+			if (!isMessageAlreadySent) {
+				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
+
+				outgoingMessageTransaction.computeNonce();
+				outgoingMessageTransaction.sign(sender);
+
+				// reset repository state to prevent deadlock
+				repository.discardChanges();
+				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_AT_REDEEM,
+					() -> String.format("Locked AT %s to %s. Waiting for AT redeem", tradeBotData.getAtAddress(), aliceNativeAddress));
+
+			return;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to switch to TRADE mode and lock trade to Alice only.
+	 * <p>
+	 * It's possible that Bob has cancelled his trade offer in the mean time, or that somehow
+	 * this process has taken so long that we've reached P2SH-A's locktime, or that someone else
+	 * has managed to trade with Bob. In any of these cases, trade-bot switches to begin the refunding process.
+	 * <p>
+	 * Assuming Bob's AT is locked to Alice, trade-bot checks AT's state data to make sure it is correct.
+	 * <p>
+	 * If all is well, trade-bot then redeems AT using Alice's secret-A, releasing Bob's QORT to Alice.
+	 * <p>
+	 * In revealing a valid secret-A, Bob can then redeem the DGB funds from P2SH-A.
+	 * <p>
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceWaitingForAtLock(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		if (aliceUnexpectedState(repository, tradeBotData, atData, crossChainTradeData))
+			return;
+
+		Digibyte digibyte = Digibyte.getInstance();
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// Refund P2SH-A if we've passed lockTime-A
+		if (NTP.getTime() >= lockTimeA * 1000L) {
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+			String p2shAddressA = digibyte.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Digibyte.getInstance().getP2shFee(feeTimestamp);
+			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(digibyte.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+				case FUNDED:
+					break;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// Already redeemed?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade completed", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+							() -> String.format("P2SH-A %s already refunded. Trade aborted", p2shAddressA));
+					return;
+
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> atData.getIsFinished()
+					? String.format("AT %s cancelled. Refunding P2SH-A %s - aborting trade", tradeBotData.getAtAddress(), p2shAddressA)
+					: String.format("LockTime-A reached, refunding P2SH-A %s - aborting trade", p2shAddressA));
+
+			return;
+		}
+
+		// We're waiting for AT to be in TRADE mode
+		if (crossChainTradeData.mode != AcctMode.TRADING)
+			return;
+
+		// AT is in TRADE mode and locked to us as checked by aliceUnexpectedState() above
+
+		// Find our MESSAGE to AT from previous state
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(tradeBotData.getTradeNativePublicKey(),
+				crossChainTradeData.qortalCreatorTradeAddress, null, null, null);
+		if (messageTransactionsData == null || messageTransactionsData.isEmpty()) {
+			LOGGER.warn(() -> String.format("Unable to find our message to trade creator %s?", crossChainTradeData.qortalCreatorTradeAddress));
+			return;
+		}
+
+		long recipientMessageTimestamp = messageTransactionsData.get(0).getTimestamp();
+		int refundTimeout = DigibyteACCTv3.calcRefundTimeout(recipientMessageTimestamp, lockTimeA);
+
+		// Our calculated refundTimeout should match AT's refundTimeout
+		if (refundTimeout != crossChainTradeData.refundTimeout) {
+			LOGGER.debug(() -> String.format("Trade AT refundTimeout '%d' doesn't match our refundTimeout '%d'", crossChainTradeData.refundTimeout, refundTimeout));
+			// We'll eventually refund
+			return;
+		}
+
+		// We're good to redeem AT
+
+		// Send 'redeem' MESSAGE to AT using both secret
+		byte[] secretA = tradeBotData.getSecret();
+		String qortalReceivingAddress = Base58.encode(tradeBotData.getReceivingAccountInfo()); // Actually contains whole address, not just PKH
+		byte[] messageData = DigibyteACCTv3.buildRedeemMessage(secretA, qortalReceivingAddress);
+		String messageRecipient = tradeBotData.getAtAddress();
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// Reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				return;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+				() -> String.format("Redeeming AT %s. Funds should arrive at %s",
+						tradeBotData.getAtAddress(), qortalReceivingAddress));
+	}
+
+	/**
+	 * Trade-bot is waiting for Alice to redeem Bob's AT, thus revealing secret-A which is required to spend the DGB funds from P2SH-A.
+	 * <p>
+	 * It's possible that Bob's AT has reached its trading timeout and automatically refunded QORT back to Bob. In which case,
+	 * trade-bot is done with this specific trade and finalizes in refunded state.
+	 * <p>
+	 * Assuming trade-bot can extract a valid secret-A from Alice's MESSAGE then trade-bot uses that to redeem the DGB funds from P2SH-A
+	 * to Bob's 'foreign'/Digibyte trade legacy-format address, as derived from trade private key.
+	 * <p>
+	 * (This could potentially be 'improved' to send DGB to any address of Bob's choosing by changing the transaction output).
+	 * <p>
+	 * If trade-bot successfully broadcasts the transaction, then this specific trade is done.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForAtRedeem(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// AT should be 'finished' once Alice has redeemed QORT funds
+		if (!atData.getIsFinished())
+			// Not finished yet
+			return;
+
+		// If AT is REFUNDED or CANCELLED then something has gone wrong
+		if (crossChainTradeData.mode == AcctMode.REFUNDED || crossChainTradeData.mode == AcctMode.CANCELLED) {
+			// Alice hasn't redeemed the QORT, so there is no point in trying to redeem the DGB
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
+
+			return;
+		}
+
+		byte[] secretA = DigibyteACCTv3.getInstance().findSecretA(repository, crossChainTradeData);
+		if (secretA == null) {
+			LOGGER.debug(() -> String.format("Unable to find secret-A from redeem message to AT %s?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		// Use secret-A to redeem P2SH-A
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		byte[] receivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+		int lockTimeA = crossChainTradeData.lockTimeA;
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTimeA, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
+		String p2shAddressA = digibyte.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Digibyte.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(digibyte.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// P2SH-A suddenly not funded? Our best bet at this point is to hope for AT auto-refund
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Double-check that we have redeemed P2SH-A...
+				break;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				// Wait for AT to auto-refund
+				return;
+
+			case FUNDED: {
+				Coin redeemAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey redeemKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = digibyte.getUnspentOutputs(p2shAddressA);
+
+				Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(digibyte.getNetworkParameters(), redeemAmount, redeemKey,
+						fundingOutputs, redeemScriptA, secretA, receivingAccountInfo);
+
+				digibyte.broadcastTransaction(p2shRedeemTransaction);
+				break;
+			}
+		}
+
+		String receivingAddress = digibyte.pkhToAddress(receivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+				() -> String.format("P2SH-A %s redeemed. Funds should arrive at %s", tradeBotData.getAtAddress(), receivingAddress));
+	}
+
+	/**
+	 * Trade-bot is attempting to refund P2SH-A.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceRefundingP2shA(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// We can't refund P2SH-A until lockTime-A has passed
+		if (NTP.getTime() <= lockTimeA * 1000L)
+			return;
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+		int medianBlockTime = digibyte.getMedianBlockTime();
+		if (medianBlockTime <= lockTimeA)
+			return;
+
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+		String p2shAddressA = digibyte.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Digibyte.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(digibyte.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// Still waiting for P2SH-A to be funded...
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Too late!
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+						() -> String.format("P2SH-A %s already spent!", p2shAddressA));
+				return;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				break;
+
+			case FUNDED:{
+				Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = digibyte.getUnspentOutputs(p2shAddressA);
+
+				// Determine receive address for refund
+				String receiveAddress = digibyte.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+				Address receiving = Address.fromString(digibyte.getNetworkParameters(), receiveAddress);
+
+				Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(digibyte.getNetworkParameters(), refundAmount, refundKey,
+						fundingOutputs, redeemScriptA, lockTimeA, receiving.getHash());
+
+				digibyte.broadcastTransaction(p2shRefundTransaction);
+				break;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+				() -> String.format("LockTime-A reached. Refunded P2SH-A %s. Trade aborted", p2shAddressA));
+	}
+
+	/**
+	 * Returns true if Alice finds AT unexpectedly cancelled, refunded, redeemed or locked to someone else.
+	 * <p>
+	 * Will automatically update trade-bot state to <tt>ALICE_REFUNDING_A</tt> or <tt>ALICE_DONE</tt> as necessary.
+	 * 
+	 * @throws DataException
+	 * @throws ForeignBlockchainException
+	 */
+	private boolean aliceUnexpectedState(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// This is OK
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.OFFERING)
+			return false;
+
+		boolean isAtLockedToUs = tradeBotData.getTradeNativeAddress().equals(crossChainTradeData.qortalPartnerAddress);
+
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.TRADING)
+			if (isAtLockedToUs) {
+				// AT is trading with us - OK
+				return false;
+			} else {
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+						() -> String.format("AT %s trading with someone else: %s. Refunding & aborting trade", tradeBotData.getAtAddress(), crossChainTradeData.qortalPartnerAddress));
+
+				return true;
+			}
+
+		if (atData.getIsFinished() && crossChainTradeData.mode == AcctMode.REDEEMED && isAtLockedToUs) {
+			// We've redeemed already?
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+					() -> String.format("AT %s already redeemed by us. Trade completed", tradeBotData.getAtAddress()));
+		} else {
+			// Any other state is not good, so start defensive refund
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> String.format("AT %s cancelled/refunded/redeemed by someone else/invalid state. Refunding & aborting trade", tradeBotData.getAtAddress()));
+		}
+
+		return true;
+	}
+
+	private long calcFeeTimestamp(int lockTimeA, int tradeTimeout) {
+		return (lockTimeA - tradeTimeout * 60) * 1000L;
+	}
+
+}

src/main/java/org/qortal/controller/tradebot/RavencoinACCTv3TradeBot.java

@@ -0,0 +1,885 @@
+package org.qortal.controller.tradebot;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.*;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.*;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+/**
+ * Performing cross-chain trading steps on behalf of user.
+ * <p>
+ * We deal with three different independent state-spaces here:
+ * <ul>
+ * 	<li>Qortal blockchain</li>
+ * 	<li>Foreign blockchain</li>
+ * 	<li>Trade-bot entries</li>
+ * </ul>
+ */
+public class RavencoinACCTv3TradeBot implements AcctTradeBot {
+
+	private static final Logger LOGGER = LogManager.getLogger(RavencoinACCTv3TradeBot.class);
+
+	public enum State implements TradeBot.StateNameAndValueSupplier {
+		BOB_WAITING_FOR_AT_CONFIRM(10, false, false),
+		BOB_WAITING_FOR_MESSAGE(15, true, true),
+		BOB_WAITING_FOR_AT_REDEEM(25, true, true),
+		BOB_DONE(30, false, false),
+		BOB_REFUNDED(35, false, false),
+
+		ALICE_WAITING_FOR_AT_LOCK(85, true, true),
+		ALICE_DONE(95, false, false),
+		ALICE_REFUNDING_A(105, true, true),
+		ALICE_REFUNDED(110, false, false);
+
+		private static final Map<Integer, State> map = stream(State.values()).collect(toMap(state -> state.value, state -> state));
+
+		public final int value;
+		public final boolean requiresAtData;
+		public final boolean requiresTradeData;
+
+		State(int value, boolean requiresAtData, boolean requiresTradeData) {
+			this.value = value;
+			this.requiresAtData = requiresAtData;
+			this.requiresTradeData = requiresTradeData;
+		}
+
+		public static State valueOf(int value) {
+			return map.get(value);
+		}
+
+		@Override
+		public String getState() {
+			return this.name();
+		}
+
+		@Override
+		public int getStateValue() {
+			return this.value;
+		}
+	}
+
+	/** Maximum time Bob waits for his AT creation transaction to be confirmed into a block. (milliseconds) */
+	private static final long MAX_AT_CONFIRMATION_PERIOD = 24 * 60 * 60 * 1000L; // ms
+
+	private static RavencoinACCTv3TradeBot instance;
+
+	private final List<String> endStates = Arrays.asList(State.BOB_DONE, State.BOB_REFUNDED, State.ALICE_DONE, State.ALICE_REFUNDING_A, State.ALICE_REFUNDED).stream()
+			.map(State::name)
+			.collect(Collectors.toUnmodifiableList());
+
+	private RavencoinACCTv3TradeBot() {
+	}
+
+	public static synchronized RavencoinACCTv3TradeBot getInstance() {
+		if (instance == null)
+			instance = new RavencoinACCTv3TradeBot();
+
+		return instance;
+	}
+
+	@Override
+	public List<String> getEndStates() {
+		return this.endStates;
+	}
+
+	/**
+	 * Creates a new trade-bot entry from the "Bob" viewpoint, i.e. OFFERing QORT in exchange for RVN.
+	 * <p>
+	 * Generates:
+	 * <ul>
+	 * 	<li>new 'trade' private key</li>
+	 * </ul>
+	 * Derives:
+	 * <ul>
+	 * 	<li>'native' (as in Qortal) public key, public key hash, address (starting with Q)</li>
+	 * 	<li>'foreign' (as in Ravencoin) public key, public key hash</li>
+	 * </ul>
+	 * A Qortal AT is then constructed including the following as constants in the 'data segment':
+	 * <ul>
+	 * 	<li>'native'/Qortal 'trade' address - used as a MESSAGE contact</li>
+	 * 	<li>'foreign'/Ravencoin public key hash - used by Alice's P2SH scripts to allow redeem</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>RVN amount expected in return by Bob (from Alice)</li>
+	 * 	<li>trading timeout, in case things go wrong and everyone needs to refund</li>
+	 * </ul>
+	 * Returns a DEPLOY_AT transaction that needs to be signed and broadcast to the Qortal network.
+	 * <p>
+	 * Trade-bot will wait for Bob's AT to be deployed before taking next step.
+	 * <p>
+	 * @param repository
+	 * @param tradeBotCreateRequest
+	 * @return raw, unsigned DEPLOY_AT transaction
+	 * @throws DataException
+	 */
+	public byte[] createTrade(Repository repository, TradeBotCreateRequest tradeBotCreateRequest) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+
+		// Convert Ravencoin receiving address into public key hash (we only support P2PKH at this time)
+		Address ravencoinReceivingAddress;
+		try {
+			ravencoinReceivingAddress = Address.fromString(Ravencoin.getInstance().getNetworkParameters(), tradeBotCreateRequest.receivingAddress);
+		} catch (AddressFormatException e) {
+			throw new DataException("Unsupported Ravencoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+		}
+		if (ravencoinReceivingAddress.getOutputScriptType() != ScriptType.P2PKH)
+			throw new DataException("Unsupported Ravencoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+
+		byte[] ravencoinReceivingAccountInfo = ravencoinReceivingAddress.getHash();
+
+		PublicKeyAccount creator = new PublicKeyAccount(repository, tradeBotCreateRequest.creatorPublicKey);
+
+		// Deploy AT
+		long timestamp = NTP.getTime();
+		byte[] reference = creator.getLastReference();
+		long fee = 0L;
+		byte[] signature = null;
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, creator.getPublicKey(), fee, signature);
+
+		String name = "QORT/RVN ACCT";
+		String description = "QORT/RVN cross-chain trade";
+		String aTType = "ACCT";
+		String tags = "ACCT QORT RVN";
+		byte[] creationBytes = RavencoinACCTv3.buildQortalAT(tradeNativeAddress, tradeForeignPublicKeyHash, tradeBotCreateRequest.qortAmount,
+				tradeBotCreateRequest.foreignAmount, tradeBotCreateRequest.tradeTimeout);
+		long amount = tradeBotCreateRequest.fundingQortAmount;
+
+		DeployAtTransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, aTType, tags, creationBytes, amount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		DeployAtTransaction.ensureATAddress(deployAtTransactionData);
+		String atAddress = deployAtTransactionData.getAtAddress();
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, RavencoinACCTv3.NAME,
+				State.BOB_WAITING_FOR_AT_CONFIRM.name(), State.BOB_WAITING_FOR_AT_CONFIRM.value,
+				creator.getAddress(), atAddress, timestamp, tradeBotCreateRequest.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				null, null,
+				SupportedBlockchain.RAVENCOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				tradeBotCreateRequest.foreignAmount, null, null, null, ravencoinReceivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Built AT %s. Waiting for deployment", atAddress));
+
+		// Attempt to backup the trade bot data
+		TradeBot.backupTradeBotData(repository, null);
+
+		// Return to user for signing and broadcast as we don't have their Qortal private key
+		try {
+			return DeployAtTransactionTransformer.toBytes(deployAtTransactionData);
+		} catch (TransformationException e) {
+			throw new DataException("Failed to transform DEPLOY_AT transaction?", e);
+		}
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint, i.e. matching RVN to an existing offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a Ravencoin wallet via <tt>xprv58</tt>.
+	 * <p>
+	 * The <tt>crossChainTradeData</tt> contains the current trade offer state
+	 * as extracted from the AT's data segment.
+	 * <p>
+	 * Access to a funded wallet is via a Ravencoin BIP32 hierarchical deterministic key,
+	 * passed via <tt>xprv58</tt>.
+	 * <b>This key will be stored in your node's database</b>
+	 * to allow trade-bot to create/fund the necessary P2SH transactions!
+	 * However, due to the nature of BIP32 keys, it is possible to give the trade-bot
+	 * only a subset of wallet access (see BIP32 for more details).
+	 * <p>
+	 * As an example, the xprv58 can be extract from a <i>legacy, password-less</i>
+	 * Electrum wallet by going to the console tab and entering:<br>
+	 * <tt>wallet.keystore.xprv</tt><br>
+	 * which should result in a base58 string starting with either 'xprv' (for Ravencoin main-net)
+	 * or 'tprv' for (Ravencoin test-net).
+	 * <p>
+	 * It is envisaged that the value in <tt>xprv58</tt> will actually come from a Qortal-UI-managed wallet.
+	 * <p>
+	 * If sufficient funds are available, <b>this method will actually fund the P2SH-A</b>
+	 * with the Ravencoin amount expected by 'Bob'.
+	 * <p>
+	 * If the Ravencoin transaction is successfully broadcast to the network then
+	 * we also send a MESSAGE to Bob's trade-bot to let them know.
+	 * <p>
+	 * The trade-bot entry is saved to the repository and the cross-chain trading process commences.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeData chosen trade OFFER that Alice wants to match
+	 * @param xprv58 funded wallet xprv in base58
+	 * @return true if P2SH-A funding transaction successfully broadcast to Ravencoin network, false otherwise
+	 * @throws DataException
+	 */
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct, CrossChainTradeData crossChainTradeData, String xprv58, String receivingAddress) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+		byte[] secretA = TradeBot.generateSecret();
+		byte[] hashOfSecretA = Crypto.hash160(secretA);
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+		byte[] receivingPublicKeyHash = Base58.decode(receivingAddress); // Actually the whole address, not just PKH
+
+		// We need to generate lockTime-A: add tradeTimeout to now
+		long now = NTP.getTime();
+		int lockTimeA = crossChainTradeData.tradeTimeout * 60 + (int) (now / 1000L);
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, RavencoinACCTv3.NAME,
+				State.ALICE_WAITING_FOR_AT_LOCK.name(), State.ALICE_WAITING_FOR_AT_LOCK.value,
+				receivingAddress, crossChainTradeData.qortalAtAddress, now, crossChainTradeData.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				secretA, hashOfSecretA,
+				SupportedBlockchain.RAVENCOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				crossChainTradeData.expectedForeignAmount, xprv58, null, lockTimeA, receivingPublicKeyHash);
+
+		// Attempt to backup the trade bot data
+		// Include tradeBotData as an additional parameter, since it's not in the repository yet
+		TradeBot.backupTradeBotData(repository, Arrays.asList(tradeBotData));
+
+		// Check we have enough funds via xprv58 to fund P2SH to cover expectedForeignAmount
+		long p2shFee;
+		try {
+			p2shFee = Ravencoin.getInstance().getP2shFee(now);
+		} catch (ForeignBlockchainException e) {
+			LOGGER.debug("Couldn't estimate Ravencoin fees?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		// Do not include fee for funding transaction as this is covered by buildSpend()
+		long amountA = crossChainTradeData.expectedForeignAmount + p2shFee /*redeeming/refunding P2SH-A*/;
+
+		// P2SH-A to be funded
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(tradeForeignPublicKeyHash, lockTimeA, crossChainTradeData.creatorForeignPKH, hashOfSecretA);
+		String p2shAddress = Ravencoin.getInstance().deriveP2shAddress(redeemScriptBytes);
+
+		// Build transaction for funding P2SH-A
+		Transaction p2shFundingTransaction = Ravencoin.getInstance().buildSpend(tradeBotData.getForeignKey(), p2shAddress, amountA);
+		if (p2shFundingTransaction == null) {
+			LOGGER.debug("Unable to build P2SH-A funding transaction - lack of funds?");
+			return ResponseResult.BALANCE_ISSUE;
+		}
+
+		try {
+			Ravencoin.getInstance().broadcastTransaction(p2shFundingTransaction);
+		} catch (ForeignBlockchainException e) {
+			// We couldn't fund P2SH-A at this time
+			LOGGER.debug("Couldn't broadcast P2SH-A funding transaction?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Attempt to send MESSAGE to Bob's Qortal trade address
+		byte[] messageData = RavencoinACCTv3.buildOfferMessage(tradeBotData.getTradeForeignPublicKeyHash(), tradeBotData.getHashOfSecret(), tradeBotData.getLockTimeA());
+		String messageRecipient = crossChainTradeData.qortalCreatorTradeAddress;
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+				return ResponseResult.NETWORK_ISSUE;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
+
+		return ResponseResult.OK;
+	}
+
+	@Override
+	public boolean canDelete(Repository repository, TradeBotData tradeBotData) throws DataException {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null)
+			return true;
+
+		// If the AT doesn't exist then we might as well let the user tidy up
+		if (!repository.getATRepository().exists(tradeBotData.getAtAddress()))
+			return true;
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+			case ALICE_DONE:
+			case BOB_DONE:
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+			case ALICE_REFUNDING_A:
+				return true;
+
+			default:
+				return false;
+		}
+	}
+
+	@Override
+	public void progress(Repository repository, TradeBotData tradeBotData) throws DataException, ForeignBlockchainException {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null) {
+			LOGGER.info(() -> String.format("Trade-bot entry for AT %s has invalid state?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		ATData atData = null;
+		CrossChainTradeData tradeData = null;
+
+		if (tradeBotState.requiresAtData) {
+			// Attempt to fetch AT data
+			atData = repository.getATRepository().fromATAddress(tradeBotData.getAtAddress());
+			if (atData == null) {
+				LOGGER.debug(() -> String.format("Unable to fetch trade AT %s from repository", tradeBotData.getAtAddress()));
+				return;
+			}
+
+			if (tradeBotState.requiresTradeData) {
+				tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+				if (tradeData == null) {
+					LOGGER.warn(() -> String.format("Unable to fetch ACCT trade data for AT %s from repository", tradeBotData.getAtAddress()));
+					return;
+				}
+			}
+		}
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+				handleBobWaitingForAtConfirm(repository, tradeBotData);
+				break;
+
+			case BOB_WAITING_FOR_MESSAGE:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForMessage(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_WAITING_FOR_AT_LOCK:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceWaitingForAtLock(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case BOB_WAITING_FOR_AT_REDEEM:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForAtRedeem(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_DONE:
+			case BOB_DONE:
+				break;
+
+			case ALICE_REFUNDING_A:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceRefundingP2shA(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+				break;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to deploy.
+	 * <p>
+	 * If AT is deployed, then trade-bot's next step is to wait for MESSAGE from Alice.
+	 */
+	private void handleBobWaitingForAtConfirm(Repository repository, TradeBotData tradeBotData) throws DataException {
+		if (!repository.getATRepository().exists(tradeBotData.getAtAddress())) {
+			if (NTP.getTime() - tradeBotData.getTimestamp() <= MAX_AT_CONFIRMATION_PERIOD)
+				return;
+
+			// We've waited ages for AT to be confirmed into a block but something has gone awry.
+			// After this long we assume transaction loss so give up with trade-bot entry too.
+			tradeBotData.setState(State.BOB_REFUNDED.name());
+			tradeBotData.setStateValue(State.BOB_REFUNDED.value);
+			tradeBotData.setTimestamp(NTP.getTime());
+			// We delete trade-bot entry here instead of saving, hence not using updateTradeBotState()
+			repository.getCrossChainRepository().delete(tradeBotData.getTradePrivateKey());
+			repository.saveChanges();
+
+			LOGGER.info(() -> String.format("AT %s never confirmed. Giving up on trade", tradeBotData.getAtAddress()));
+			TradeBot.notifyStateChange(tradeBotData);
+			return;
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_MESSAGE,
+				() -> String.format("AT %s confirmed ready. Waiting for trade message", tradeBotData.getAtAddress()));
+	}
+
+	/**
+	 * Trade-bot is waiting for MESSAGE from Alice's trade-bot, containing Alice's trade info.
+	 * <p>
+	 * It's possible Bob has cancelling his trade offer, receiving an automatic QORT refund,
+	 * in which case trade-bot is done with this specific trade and finalizes on refunded state.
+	 * <p>
+	 * Assuming trade is still on offer, trade-bot checks the contents of MESSAGE from Alice's trade-bot.
+	 * <p>
+	 * Details from Alice are used to derive P2SH-A address and this is checked for funding balance.
+	 * <p>
+	 * Assuming P2SH-A has at least expected Ravencoin balance,
+	 * Bob's trade-bot constructs a zero-fee, PoW MESSAGE to send to Bob's AT with more trade details.
+	 * <p>
+	 * On processing this MESSAGE, Bob's AT should switch into 'TRADE' mode and only trade with Alice.
+	 * <p>
+	 * Trade-bot's next step is to wait for Alice to redeem the AT, which will allow Bob to
+	 * extract secret-A needed to redeem Alice's P2SH.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForMessage(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// If AT has finished then Bob likely cancelled his trade offer
+		if (atData.getIsFinished()) {
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s cancelled - trading aborted", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		String address = tradeBotData.getTradeNativeAddress();
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, address, null, null, null);
+
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			if (messageTransactionData.isText())
+				continue;
+
+			// We're expecting: HASH160(secret-A), Alice's Ravencoin pubkeyhash and lockTime-A
+			byte[] messageData = messageTransactionData.getData();
+			RavencoinACCTv3.OfferMessageData offerMessageData = RavencoinACCTv3.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				continue;
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerRavencoinPKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+			long messageTimestamp = messageTransactionData.getTimestamp();
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(messageTimestamp, lockTimeA);
+
+			// Determine P2SH-A address and confirm funded
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(aliceForeignPublicKeyHash, lockTimeA, tradeBotData.getTradeForeignPublicKeyHash(), hashOfSecretA);
+			String p2shAddressA = ravencoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Ravencoin.getInstance().getP2shFee(feeTimestamp);
+			final long minimumAmountA = tradeBotData.getForeignAmount() + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(ravencoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+					// There might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// We've already redeemed this?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade complete", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					// This P2SH-A is burnt, but there might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case FUNDED:
+					// Fall-through out of switch...
+					break;
+			}
+
+			// Good to go - send MESSAGE to AT
+
+			String aliceNativeAddress = Crypto.toAddress(messageTransactionData.getCreatorPublicKey());
+
+			// Build outgoing message, padding each part to 32 bytes to make it easier for AT to consume
+			byte[] outgoingMessageData = RavencoinACCTv3.buildTradeMessage(aliceNativeAddress, aliceForeignPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			String messageRecipient = tradeBotData.getAtAddress();
+
+			boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, outgoingMessageData);
+			if (!isMessageAlreadySent) {
+				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
+
+				outgoingMessageTransaction.computeNonce();
+				outgoingMessageTransaction.sign(sender);
+
+				// reset repository state to prevent deadlock
+				repository.discardChanges();
+				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_AT_REDEEM,
+					() -> String.format("Locked AT %s to %s. Waiting for AT redeem", tradeBotData.getAtAddress(), aliceNativeAddress));
+
+			return;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to switch to TRADE mode and lock trade to Alice only.
+	 * <p>
+	 * It's possible that Bob has cancelled his trade offer in the mean time, or that somehow
+	 * this process has taken so long that we've reached P2SH-A's locktime, or that someone else
+	 * has managed to trade with Bob. In any of these cases, trade-bot switches to begin the refunding process.
+	 * <p>
+	 * Assuming Bob's AT is locked to Alice, trade-bot checks AT's state data to make sure it is correct.
+	 * <p>
+	 * If all is well, trade-bot then redeems AT using Alice's secret-A, releasing Bob's QORT to Alice.
+	 * <p>
+	 * In revealing a valid secret-A, Bob can then redeem the RVN funds from P2SH-A.
+	 * <p>
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceWaitingForAtLock(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		if (aliceUnexpectedState(repository, tradeBotData, atData, crossChainTradeData))
+			return;
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// Refund P2SH-A if we've passed lockTime-A
+		if (NTP.getTime() >= lockTimeA * 1000L) {
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+			String p2shAddressA = ravencoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Ravencoin.getInstance().getP2shFee(feeTimestamp);
+			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(ravencoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+				case FUNDED:
+					break;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// Already redeemed?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade completed", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+							() -> String.format("P2SH-A %s already refunded. Trade aborted", p2shAddressA));
+					return;
+
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> atData.getIsFinished()
+					? String.format("AT %s cancelled. Refunding P2SH-A %s - aborting trade", tradeBotData.getAtAddress(), p2shAddressA)
+					: String.format("LockTime-A reached, refunding P2SH-A %s - aborting trade", p2shAddressA));
+
+			return;
+		}
+
+		// We're waiting for AT to be in TRADE mode
+		if (crossChainTradeData.mode != AcctMode.TRADING)
+			return;
+
+		// AT is in TRADE mode and locked to us as checked by aliceUnexpectedState() above
+
+		// Find our MESSAGE to AT from previous state
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(tradeBotData.getTradeNativePublicKey(),
+				crossChainTradeData.qortalCreatorTradeAddress, null, null, null);
+		if (messageTransactionsData == null || messageTransactionsData.isEmpty()) {
+			LOGGER.warn(() -> String.format("Unable to find our message to trade creator %s?", crossChainTradeData.qortalCreatorTradeAddress));
+			return;
+		}
+
+		long recipientMessageTimestamp = messageTransactionsData.get(0).getTimestamp();
+		int refundTimeout = RavencoinACCTv3.calcRefundTimeout(recipientMessageTimestamp, lockTimeA);
+
+		// Our calculated refundTimeout should match AT's refundTimeout
+		if (refundTimeout != crossChainTradeData.refundTimeout) {
+			LOGGER.debug(() -> String.format("Trade AT refundTimeout '%d' doesn't match our refundTimeout '%d'", crossChainTradeData.refundTimeout, refundTimeout));
+			// We'll eventually refund
+			return;
+		}
+
+		// We're good to redeem AT
+
+		// Send 'redeem' MESSAGE to AT using both secret
+		byte[] secretA = tradeBotData.getSecret();
+		String qortalReceivingAddress = Base58.encode(tradeBotData.getReceivingAccountInfo()); // Actually contains whole address, not just PKH
+		byte[] messageData = RavencoinACCTv3.buildRedeemMessage(secretA, qortalReceivingAddress);
+		String messageRecipient = tradeBotData.getAtAddress();
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// Reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				return;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+				() -> String.format("Redeeming AT %s. Funds should arrive at %s",
+						tradeBotData.getAtAddress(), qortalReceivingAddress));
+	}
+
+	/**
+	 * Trade-bot is waiting for Alice to redeem Bob's AT, thus revealing secret-A which is required to spend the RVN funds from P2SH-A.
+	 * <p>
+	 * It's possible that Bob's AT has reached its trading timeout and automatically refunded QORT back to Bob. In which case,
+	 * trade-bot is done with this specific trade and finalizes in refunded state.
+	 * <p>
+	 * Assuming trade-bot can extract a valid secret-A from Alice's MESSAGE then trade-bot uses that to redeem the RVN funds from P2SH-A
+	 * to Bob's 'foreign'/Ravencoin trade legacy-format address, as derived from trade private key.
+	 * <p>
+	 * (This could potentially be 'improved' to send RVN to any address of Bob's choosing by changing the transaction output).
+	 * <p>
+	 * If trade-bot successfully broadcasts the transaction, then this specific trade is done.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForAtRedeem(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// AT should be 'finished' once Alice has redeemed QORT funds
+		if (!atData.getIsFinished())
+			// Not finished yet
+			return;
+
+		// If AT is REFUNDED or CANCELLED then something has gone wrong
+		if (crossChainTradeData.mode == AcctMode.REFUNDED || crossChainTradeData.mode == AcctMode.CANCELLED) {
+			// Alice hasn't redeemed the QORT, so there is no point in trying to redeem the RVN
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
+
+			return;
+		}
+
+		byte[] secretA = RavencoinACCTv3.getInstance().findSecretA(repository, crossChainTradeData);
+		if (secretA == null) {
+			LOGGER.debug(() -> String.format("Unable to find secret-A from redeem message to AT %s?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		// Use secret-A to redeem P2SH-A
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		byte[] receivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+		int lockTimeA = crossChainTradeData.lockTimeA;
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTimeA, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
+		String p2shAddressA = ravencoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Ravencoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(ravencoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// P2SH-A suddenly not funded? Our best bet at this point is to hope for AT auto-refund
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Double-check that we have redeemed P2SH-A...
+				break;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				// Wait for AT to auto-refund
+				return;
+
+			case FUNDED: {
+				Coin redeemAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey redeemKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = ravencoin.getUnspentOutputs(p2shAddressA);
+
+				Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(ravencoin.getNetworkParameters(), redeemAmount, redeemKey,
+						fundingOutputs, redeemScriptA, secretA, receivingAccountInfo);
+
+				ravencoin.broadcastTransaction(p2shRedeemTransaction);
+				break;
+			}
+		}
+
+		String receivingAddress = ravencoin.pkhToAddress(receivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+				() -> String.format("P2SH-A %s redeemed. Funds should arrive at %s", tradeBotData.getAtAddress(), receivingAddress));
+	}
+
+	/**
+	 * Trade-bot is attempting to refund P2SH-A.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceRefundingP2shA(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// We can't refund P2SH-A until lockTime-A has passed
+		if (NTP.getTime() <= lockTimeA * 1000L)
+			return;
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+		int medianBlockTime = ravencoin.getMedianBlockTime();
+		if (medianBlockTime <= lockTimeA)
+			return;
+
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+		String p2shAddressA = ravencoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Ravencoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(ravencoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// Still waiting for P2SH-A to be funded...
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Too late!
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+						() -> String.format("P2SH-A %s already spent!", p2shAddressA));
+				return;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				break;
+
+			case FUNDED:{
+				Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = ravencoin.getUnspentOutputs(p2shAddressA);
+
+				// Determine receive address for refund
+				String receiveAddress = ravencoin.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+				Address receiving = Address.fromString(ravencoin.getNetworkParameters(), receiveAddress);
+
+				Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(ravencoin.getNetworkParameters(), refundAmount, refundKey,
+						fundingOutputs, redeemScriptA, lockTimeA, receiving.getHash());
+
+				ravencoin.broadcastTransaction(p2shRefundTransaction);
+				break;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+				() -> String.format("LockTime-A reached. Refunded P2SH-A %s. Trade aborted", p2shAddressA));
+	}
+
+	/**
+	 * Returns true if Alice finds AT unexpectedly cancelled, refunded, redeemed or locked to someone else.
+	 * <p>
+	 * Will automatically update trade-bot state to <tt>ALICE_REFUNDING_A</tt> or <tt>ALICE_DONE</tt> as necessary.
+	 * 
+	 * @throws DataException
+	 * @throws ForeignBlockchainException
+	 */
+	private boolean aliceUnexpectedState(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// This is OK
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.OFFERING)
+			return false;
+
+		boolean isAtLockedToUs = tradeBotData.getTradeNativeAddress().equals(crossChainTradeData.qortalPartnerAddress);
+
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.TRADING)
+			if (isAtLockedToUs) {
+				// AT is trading with us - OK
+				return false;
+			} else {
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+						() -> String.format("AT %s trading with someone else: %s. Refunding & aborting trade", tradeBotData.getAtAddress(), crossChainTradeData.qortalPartnerAddress));
+
+				return true;
+			}
+
+		if (atData.getIsFinished() && crossChainTradeData.mode == AcctMode.REDEEMED && isAtLockedToUs) {
+			// We've redeemed already?
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+					() -> String.format("AT %s already redeemed by us. Trade completed", tradeBotData.getAtAddress()));
+		} else {
+			// Any other state is not good, so start defensive refund
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> String.format("AT %s cancelled/refunded/redeemed by someone else/invalid state. Refunding & aborting trade", tradeBotData.getAtAddress()));
+		}
+
+		return true;
+	}
+
+	private long calcFeeTimestamp(int lockTimeA, int tradeTimeout) {
+		return (lockTimeA - tradeTimeout * 60) * 1000L;
+	}
+
+}

src/main/java/org/qortal/controller/tradebot/TradeBot.java

@@ -100,6 +100,8 @@ public class TradeBot implements Listener {
 		acctTradeBotSuppliers.put(DogecoinACCTv1.class, DogecoinACCTv1TradeBot::getInstance);
 		acctTradeBotSuppliers.put(DogecoinACCTv2.class, DogecoinACCTv2TradeBot::getInstance);
 		acctTradeBotSuppliers.put(DogecoinACCTv3.class, DogecoinACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(DigibyteACCTv3.class, DigibyteACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(RavencoinACCTv3.class, RavencoinACCTv3TradeBot::getInstance);
 	}
 
 	private static TradeBot instance;

src/main/java/org/qortal/crosschain/Digibyte.java

@@ -0,0 +1,171 @@
+package org.qortal.crosschain;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.Map;
+
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.params.RegTestParams;
+import org.bitcoinj.params.TestNet3Params;
+import org.libdohj.params.DigibyteMainNetParams;
+import org.qortal.crosschain.ElectrumX.Server;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
+import org.qortal.settings.Settings;
+
+public class Digibyte extends Bitcoiny {
+
+	public static final String CURRENCY_CODE = "DGB";
+
+	private static final Coin DEFAULT_FEE_PER_KB = Coin.valueOf(100000); // 0.001 DGB per 1000 bytes
+
+	private static final long MINIMUM_ORDER_AMOUNT = 1000000; // 0.01 DGB minimum order, to avoid dust errors
+
+	// Temporary values until a dynamic fee system is written.
+	private static final long MAINNET_FEE = 10000L;
+	private static final long NON_MAINNET_FEE = 10000L; // enough for TESTNET3 and should be OK for REGTEST
+
+	private static final Map<ConnectionType, Integer> DEFAULT_ELECTRUMX_PORTS = new EnumMap<>(ConnectionType.class);
+	static {
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.TCP, 50001);
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.SSL, 50002);
+	}
+
+	public enum DigibyteNet {
+		MAIN {
+			@Override
+			public NetworkParameters getParams() {
+				return DigibyteMainNetParams.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(
+						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=dgb
+						new Server("electrum1.cipig.net", ConnectionType.SSL, 20059),
+						new Server("electrum2.cipig.net", ConnectionType.SSL, 20059),
+						new Server("electrum3.cipig.net", ConnectionType.SSL, 20059));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "7497ea1b465eb39f1c8f507bc877078fe016d6fcb6dfad3a64c98dcc6e1e8496";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				// TODO: This will need to be replaced with something better in the near future!
+				return MAINNET_FEE;
+			}
+		},
+		TEST3 {
+			@Override
+			public NetworkParameters getParams() {
+				return TestNet3Params.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(); // TODO: find testnet servers
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "308ea0711d5763be2995670dd9ca9872753561285a84da1d58be58acaa822252";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		},
+		REGTEST {
+			@Override
+			public NetworkParameters getParams() {
+				return RegTestParams.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(
+						new Server("localhost", ConnectionType.TCP, 50001),
+						new Server("localhost", ConnectionType.SSL, 50002));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				// This is unique to each regtest instance
+				return null;
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		};
+
+		public abstract NetworkParameters getParams();
+		public abstract Collection<Server> getServers();
+		public abstract String getGenesisHash();
+		public abstract long getP2shFee(Long timestamp) throws ForeignBlockchainException;
+	}
+
+	private static Digibyte instance;
+
+	private final DigibyteNet digibyteNet;
+
+	// Constructors and instance
+
+	private Digibyte(DigibyteNet digibyteNet, BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		super(blockchain, bitcoinjContext, currencyCode);
+		this.digibyteNet = digibyteNet;
+
+		LOGGER.info(() -> String.format("Starting Digibyte support using %s", this.digibyteNet.name()));
+	}
+
+	public static synchronized Digibyte getInstance() {
+		if (instance == null) {
+			DigibyteNet digibyteNet = Settings.getInstance().getDigibyteNet();
+
+			BitcoinyBlockchainProvider electrumX = new ElectrumX("Digibyte-" + digibyteNet.name(), digibyteNet.getGenesisHash(), digibyteNet.getServers(), DEFAULT_ELECTRUMX_PORTS);
+			Context bitcoinjContext = new Context(digibyteNet.getParams());
+
+			instance = new Digibyte(digibyteNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+		}
+
+		return instance;
+	}
+
+	// Getters & setters
+
+	public static synchronized void resetForTesting() {
+		instance = null;
+	}
+
+	// Actual useful methods for use by other classes
+
+	@Override
+	public Coin getFeePerKb() {
+		return DEFAULT_FEE_PER_KB;
+	}
+
+	@Override
+	public long getMinimumOrderAmount() {
+		return MINIMUM_ORDER_AMOUNT;
+	}
+
+	/**
+	 * Returns estimated DGB fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes, or throws ForeignBlockchainException if something went wrong
+	 */
+	@Override
+	public long getP2shFee(Long timestamp) throws ForeignBlockchainException {
+		return this.digibyteNet.getP2shFee(timestamp);
+	}
+
+}

src/main/java/org/qortal/crosschain/DigibyteACCTv3.java

@@ -0,0 +1,858 @@
+package org.qortal.crosschain;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.ciyam.at.*;
+import org.qortal.account.Account;
+import org.qortal.asset.Asset;
+import org.qortal.at.QortalFunctionCode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.utils.Base58;
+import org.qortal.utils.BitTwiddling;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.ciyam.at.OpCode.calcOffset;
+
+/**
+ * Cross-chain trade AT
+ * 
+ * <p>
+ * <ul>
+ * <li>Bob generates Digibyte & Qortal 'trade' keys
+ * 		<ul>
+ * 			<li>private key required to sign P2SH redeem tx</li>
+ * 			<li>private key could be used to create 'secret' (e.g. double-SHA256)</li>
+ * 			<li>encrypted private key could be stored in Qortal AT for access by Bob from any node</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob deploys Qortal AT
+ * 		<ul>
+ * 		</ul>
+ * </li>
+ * <li>Alice finds Qortal AT and wants to trade
+ * 		<ul>
+ * 			<li>Alice generates Digibyte & Qortal 'trade' keys</li>
+ * 			<li>Alice funds Digibyte P2SH-A</li>
+ * 			<li>Alice sends 'offer' MESSAGE to Bob from her Qortal trade address, containing:
+ * 				<ul>
+ * 					<li>hash-of-secret-A</li>
+ * 					<li>her 'trade' Digibyte PKH</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob receives "offer" MESSAGE
+ * 		<ul>
+ * 			<li>Checks Alice's P2SH-A</li>
+ * 			<li>Sends 'trade' MESSAGE to Qortal AT from his trade address, containing:
+ * 				<ul>
+ * 					<li>Alice's trade Qortal address</li>
+ * 					<li>Alice's trade Digibyte PKH</li>
+ * 					<li>hash-of-secret-A</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Alice checks Qortal AT to confirm it's locked to her
+ * 		<ul>
+ * 			<li>Alice sends 'redeem' MESSAGE to Qortal AT from her trade address, containing:
+ * 				<ul>
+ * 					<li>secret-A</li>
+ * 					<li>Qortal receiving address of her chosing</li>
+ * 				</ul>
+ * 			</li>
+ * 			<li>AT's QORT funds are sent to Qortal receiving address</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob checks AT, extracts secret-A
+ * 		<ul>
+ * 			<li>Bob redeems P2SH-A using his Digibyte trade key and secret-A</li>
+ * 			<li>P2SH-A DGB funds end up at Digibyte address determined by redeem transaction output(s)</li>
+ * 		</ul>
+ * </li>
+ * </ul>
+ */
+public class DigibyteACCTv3 implements ACCT {
+
+	private static final Logger LOGGER = LogManager.getLogger(DigibyteACCTv3.class);
+
+	public static final String NAME = DigibyteACCTv3.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("e6a7dcd87296fae3ce7d80183bf7660c8e2cb4f8746c6a0421a17148f87a0e1d").asBytes(); // SHA256 of AT code bytes
+
+	public static final int SECRET_LENGTH = 32;
+
+	/** <b>Value</b> offset into AT segment where 'mode' variable (long) is stored. (Multiply by MachineState.VALUE_SIZE for byte offset). */
+	private static final int MODE_VALUE_OFFSET = 61;
+	/** <b>Byte</b> offset into AT state data where 'mode' variable (long) is stored. */
+	public static final int MODE_BYTE_OFFSET = MachineState.HEADER_LENGTH + (MODE_VALUE_OFFSET * MachineState.VALUE_SIZE);
+
+	public static class OfferMessageData {
+		public byte[] partnerDigibytePKH;
+		public byte[] hashOfSecretA;
+		public long lockTimeA;
+	}
+	public static final int OFFER_MESSAGE_LENGTH = 20 /*partnerDigibytePKH*/ + 20 /*hashOfSecretA*/ + 8 /*lockTimeA*/;
+	public static final int TRADE_MESSAGE_LENGTH = 32 /*partner's Qortal trade address (padded from 25 to 32)*/
+			+ 24 /*partner's Digibyte PKH (padded from 20 to 24)*/
+			+ 8 /*AT trade timeout (minutes)*/
+			+ 24 /*hash of secret-A (padded from 20 to 24)*/
+			+ 8 /*lockTimeA*/;
+	public static final int REDEEM_MESSAGE_LENGTH = 32 /*secret-A*/ + 32 /*partner's Qortal receiving address padded from 25 to 32*/;
+	public static final int CANCEL_MESSAGE_LENGTH = 32 /*AT creator's Qortal address*/;
+
+	private static DigibyteACCTv3 instance;
+
+	private DigibyteACCTv3() {
+	}
+
+	public static synchronized DigibyteACCTv3 getInstance() {
+		if (instance == null)
+			instance = new DigibyteACCTv3();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Digibyte.getInstance();
+	}
+
+	/**
+	 * Returns Qortal AT creation bytes for cross-chain trading AT.
+	 * <p>
+	 * <tt>tradeTimeout</tt> (minutes) is the time window for the trade partner to send the
+	 * 32-byte secret to the AT, before the AT automatically refunds the AT's creator.
+	 * 
+	 * @param creatorTradeAddress AT creator's trade Qortal address
+	 * @param digibytePublicKeyHash 20-byte HASH160 of creator's trade Digibyte public key
+	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
+	 * @param digibyteAmount how much DGB the AT creator is expecting to trade
+	 * @param tradeTimeout suggested timeout for entire trade
+	 */
+	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] digibytePublicKeyHash, long qortAmount, long digibyteAmount, int tradeTimeout) {
+		if (digibytePublicKeyHash.length != 20)
+			throw new IllegalArgumentException("Digibyte public key hash should be 20 bytes");
+
+		// Labels for data segment addresses
+		int addrCounter = 0;
+
+		// Constants (with corresponding dataByteBuffer.put*() calls below)
+
+		final int addrCreatorTradeAddress1 = addrCounter++;
+		final int addrCreatorTradeAddress2 = addrCounter++;
+		final int addrCreatorTradeAddress3 = addrCounter++;
+		final int addrCreatorTradeAddress4 = addrCounter++;
+
+		final int addrDigibytePublicKeyHash = addrCounter;
+		addrCounter += 4;
+
+		final int addrQortAmount = addrCounter++;
+		final int addrDigibyteAmount = addrCounter++;
+		final int addrTradeTimeout = addrCounter++;
+
+		final int addrMessageTxnType = addrCounter++;
+		final int addrExpectedTradeMessageLength = addrCounter++;
+		final int addrExpectedRedeemMessageLength = addrCounter++;
+
+		final int addrCreatorAddressPointer = addrCounter++;
+		final int addrQortalPartnerAddressPointer = addrCounter++;
+		final int addrMessageSenderPointer = addrCounter++;
+
+		final int addrTradeMessagePartnerDigibytePKHOffset = addrCounter++;
+		final int addrPartnerDigibytePKHPointer = addrCounter++;
+		final int addrTradeMessageHashOfSecretAOffset = addrCounter++;
+		final int addrHashOfSecretAPointer = addrCounter++;
+
+		final int addrRedeemMessageReceivingAddressOffset = addrCounter++;
+
+		final int addrMessageDataPointer = addrCounter++;
+		final int addrMessageDataLength = addrCounter++;
+
+		final int addrPartnerReceivingAddressPointer = addrCounter++;
+
+		final int addrEndOfConstants = addrCounter;
+
+		// Variables
+
+		final int addrCreatorAddress1 = addrCounter++;
+		final int addrCreatorAddress2 = addrCounter++;
+		final int addrCreatorAddress3 = addrCounter++;
+		final int addrCreatorAddress4 = addrCounter++;
+
+		final int addrQortalPartnerAddress1 = addrCounter++;
+		final int addrQortalPartnerAddress2 = addrCounter++;
+		final int addrQortalPartnerAddress3 = addrCounter++;
+		final int addrQortalPartnerAddress4 = addrCounter++;
+
+		final int addrLockTimeA = addrCounter++;
+		final int addrRefundTimeout = addrCounter++;
+		final int addrRefundTimestamp = addrCounter++;
+		final int addrLastTxnTimestamp = addrCounter++;
+		final int addrBlockTimestamp = addrCounter++;
+		final int addrTxnType = addrCounter++;
+		final int addrResult = addrCounter++;
+
+		final int addrMessageSender1 = addrCounter++;
+		final int addrMessageSender2 = addrCounter++;
+		final int addrMessageSender3 = addrCounter++;
+		final int addrMessageSender4 = addrCounter++;
+
+		final int addrMessageLength = addrCounter++;
+
+		final int addrMessageData = addrCounter;
+		addrCounter += 4;
+
+		final int addrHashOfSecretA = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerDigibytePKH = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerReceivingAddress = addrCounter;
+		addrCounter += 4;
+
+		final int addrMode = addrCounter++;
+		assert addrMode == MODE_VALUE_OFFSET : String.format("addrMode %d does not match MODE_VALUE_OFFSET %d", addrMode, MODE_VALUE_OFFSET);
+
+		// Data segment
+		ByteBuffer dataByteBuffer = ByteBuffer.allocate(addrCounter * MachineState.VALUE_SIZE);
+
+		// AT creator's trade Qortal address, decoded from Base58
+		assert dataByteBuffer.position() == addrCreatorTradeAddress1 * MachineState.VALUE_SIZE : "addrCreatorTradeAddress1 incorrect";
+		byte[] creatorTradeAddressBytes = Base58.decode(creatorTradeAddress);
+		dataByteBuffer.put(Bytes.ensureCapacity(creatorTradeAddressBytes, 32, 0));
+
+		// Digibyte public key hash
+		assert dataByteBuffer.position() == addrDigibytePublicKeyHash * MachineState.VALUE_SIZE : "addrDigibytePublicKeyHash incorrect";
+		dataByteBuffer.put(Bytes.ensureCapacity(digibytePublicKeyHash, 32, 0));
+
+		// Redeem Qort amount
+		assert dataByteBuffer.position() == addrQortAmount * MachineState.VALUE_SIZE : "addrQortAmount incorrect";
+		dataByteBuffer.putLong(qortAmount);
+
+		// Expected Digibyte amount
+		assert dataByteBuffer.position() == addrDigibyteAmount * MachineState.VALUE_SIZE : "addrDigibyteAmount incorrect";
+		dataByteBuffer.putLong(digibyteAmount);
+
+		// Suggested trade timeout (minutes)
+		assert dataByteBuffer.position() == addrTradeTimeout * MachineState.VALUE_SIZE : "addrTradeTimeout incorrect";
+		dataByteBuffer.putLong(tradeTimeout);
+
+		// We're only interested in MESSAGE transactions
+		assert dataByteBuffer.position() == addrMessageTxnType * MachineState.VALUE_SIZE : "addrMessageTxnType incorrect";
+		dataByteBuffer.putLong(API.ATTransactionType.MESSAGE.value);
+
+		// Expected length of 'trade' MESSAGE data from AT creator
+		assert dataByteBuffer.position() == addrExpectedTradeMessageLength * MachineState.VALUE_SIZE : "addrExpectedTradeMessageLength incorrect";
+		dataByteBuffer.putLong(TRADE_MESSAGE_LENGTH);
+
+		// Expected length of 'redeem' MESSAGE data from trade partner
+		assert dataByteBuffer.position() == addrExpectedRedeemMessageLength * MachineState.VALUE_SIZE : "addrExpectedRedeemMessageLength incorrect";
+		dataByteBuffer.putLong(REDEEM_MESSAGE_LENGTH);
+
+		// Index into data segment of AT creator's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrCreatorAddressPointer * MachineState.VALUE_SIZE : "addrCreatorAddressPointer incorrect";
+		dataByteBuffer.putLong(addrCreatorAddress1);
+
+		// Index into data segment of partner's Qortal address, used by SET_B_IND
+		assert dataByteBuffer.position() == addrQortalPartnerAddressPointer * MachineState.VALUE_SIZE : "addrQortalPartnerAddressPointer incorrect";
+		dataByteBuffer.putLong(addrQortalPartnerAddress1);
+
+		// Index into data segment of (temporary) transaction's sender's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrMessageSenderPointer * MachineState.VALUE_SIZE : "addrMessageSenderPointer incorrect";
+		dataByteBuffer.putLong(addrMessageSender1);
+
+		// Offset into 'trade' MESSAGE data payload for extracting partner's Digibyte PKH
+		assert dataByteBuffer.position() == addrTradeMessagePartnerDigibytePKHOffset * MachineState.VALUE_SIZE : "addrTradeMessagePartnerDigibytePKHOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Index into data segment of partner's Digibyte PKH, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerDigibytePKHPointer * MachineState.VALUE_SIZE : "addrPartnerDigibytePKHPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerDigibytePKH);
+
+		// Offset into 'trade' MESSAGE data payload for extracting hash-of-secret-A
+		assert dataByteBuffer.position() == addrTradeMessageHashOfSecretAOffset * MachineState.VALUE_SIZE : "addrTradeMessageHashOfSecretAOffset incorrect";
+		dataByteBuffer.putLong(64L);
+
+		// Index into data segment to hash of secret A, used by GET_B_IND
+		assert dataByteBuffer.position() == addrHashOfSecretAPointer * MachineState.VALUE_SIZE : "addrHashOfSecretAPointer incorrect";
+		dataByteBuffer.putLong(addrHashOfSecretA);
+
+		// Offset into 'redeem' MESSAGE data payload for extracting Qortal receiving address
+		assert dataByteBuffer.position() == addrRedeemMessageReceivingAddressOffset * MachineState.VALUE_SIZE : "addrRedeemMessageReceivingAddressOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Source location and length for hashing any passed secret
+		assert dataByteBuffer.position() == addrMessageDataPointer * MachineState.VALUE_SIZE : "addrMessageDataPointer incorrect";
+		dataByteBuffer.putLong(addrMessageData);
+		assert dataByteBuffer.position() == addrMessageDataLength * MachineState.VALUE_SIZE : "addrMessageDataLength incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Pointer into data segment of where to save partner's receiving Qortal address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerReceivingAddressPointer * MachineState.VALUE_SIZE : "addrPartnerReceivingAddressPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerReceivingAddress);
+
+		assert dataByteBuffer.position() == addrEndOfConstants * MachineState.VALUE_SIZE : "dataByteBuffer position not at end of constants";
+
+		// Code labels
+		Integer labelRefund = null;
+
+		Integer labelTradeTxnLoop = null;
+		Integer labelCheckTradeTxn = null;
+		Integer labelCheckCancelTxn = null;
+		Integer labelNotTradeNorCancelTxn = null;
+		Integer labelCheckNonRefundTradeTxn = null;
+		Integer labelTradeTxnExtract = null;
+		Integer labelRedeemTxnLoop = null;
+		Integer labelCheckRedeemTxn = null;
+		Integer labelCheckRedeemTxnSender = null;
+		Integer labelPayout = null;
+
+		ByteBuffer codeByteBuffer = ByteBuffer.allocate(768);
+
+		// Two-pass version
+		for (int pass = 0; pass < 2; ++pass) {
+			codeByteBuffer.clear();
+
+			try {
+				/* Initialization */
+
+				// Use AT creation 'timestamp' as starting point for finding transactions sent to AT
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_CREATION_TIMESTAMP, addrLastTxnTimestamp));
+
+				/* NOP - to ensure DIGIBYTE ACCT is unique */
+				codeByteBuffer.put(OpCode.NOP.compile());
+
+				// Load B register with AT creator's address so we can save it into addrCreatorAddress1-4
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_CREATOR_INTO_B));
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrCreatorAddressPointer));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for message from AT creator's trade address containing trade partner details, or AT owner's address to cancel offer */
+
+				/* Transaction processing loop */
+				labelTradeTxnLoop = codeByteBuffer.position();
+
+				/* Sleep until message arrives */
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.SLEEP_UNTIL_MESSAGE.value, addrLastTxnTimestamp));
+
+				// Find next transaction (if any) to this AT since the last one (referenced by addrLastTxnTimestamp)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrResult to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckTradeTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckTradeTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelTradeTxnLoop)));
+
+				/* Check transaction's sender. We're expecting AT creator's trade address for 'trade' message, or AT creator's own address for 'cancel' message. */
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of message sender's address with AT creator's trade address. If they don't match, check for cancel situation.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorTradeAddress1, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorTradeAddress2, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorTradeAddress3, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorTradeAddress4, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				// Message sender's address matches AT creator's trade address so go process 'trade' message
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelCheckNonRefundTradeTxn == null ? 0 : labelCheckNonRefundTradeTxn));
+
+				/* Checking message sender for possible cancel message */
+				labelCheckCancelTxn = codeByteBuffer.position();
+
+				// Compare each part of message sender's address with AT creator's address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorAddress1, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorAddress2, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorAddress3, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorAddress4, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				// Partner address is AT creator's address, so cancel offer and finish.
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.CANCELLED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				/* Not trade nor cancel message */
+				labelNotTradeNorCancelTxn = codeByteBuffer.position();
+
+				// Loop to find another transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Possible switch-to-trade-mode message */
+				labelCheckNonRefundTradeTxn = codeByteBuffer.position();
+
+				// Check 'trade' message we received has expected number of message bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to info extraction code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedTradeMessageLength, calcOffset(codeByteBuffer, labelTradeTxnExtract)));
+				// Message length didn't match - go back to finding another 'trade' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Extracting info from 'trade' MESSAGE transaction */
+				labelTradeTxnExtract = codeByteBuffer.position();
+
+				// Extract message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrQortalPartnerAddress1 (as pointed to by addrQortalPartnerAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrQortalPartnerAddressPointer));
+
+				// Extract trade partner's Digibyte public key hash (PKH) from message into B
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessagePartnerDigibytePKHOffset));
+				// Store partner's Digibyte PKH (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerDigibytePKHPointer));
+				// Extract AT trade timeout (minutes) (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrRefundTimeout));
+
+				// Grab next 32 bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessageHashOfSecretAOffset));
+
+				// Extract hash-of-secret-A (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrHashOfSecretAPointer));
+				// Extract lockTime-A (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrLockTimeA));
+
+				// Calculate trade timeout refund 'timestamp' by adding addrRefundTimeout minutes to this transaction's 'timestamp', then save into addrRefundTimestamp
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.ADD_MINUTES_TO_TIMESTAMP, addrRefundTimestamp, addrLastTxnTimestamp, addrRefundTimeout));
+
+				/* We are in 'trade mode' */
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.TRADING.value));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for trade timeout or 'redeem' MESSAGE from Qortal trade partner */
+
+				// Fetch current block 'timestamp'
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_BLOCK_TIMESTAMP, addrBlockTimestamp));
+				// If we're not past refund 'timestamp' then look for next transaction
+				codeByteBuffer.put(OpCode.BLT_DAT.compile(addrBlockTimestamp, addrRefundTimestamp, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				// We're past refund 'timestamp' so go refund everything back to AT creator
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRefund == null ? 0 : labelRefund));
+
+				/* Transaction processing loop */
+				labelRedeemTxnLoop = codeByteBuffer.position();
+
+				// Find next transaction to this AT since the last one (if any)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrComparator to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckRedeemTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckRedeemTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check message payload length */
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to sender checking code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedRedeemMessageLength, calcOffset(codeByteBuffer, labelCheckRedeemTxnSender)));
+				// Message length didn't match - go back to finding another 'redeem' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Check transaction's sender */
+				labelCheckRedeemTxnSender = codeByteBuffer.position();
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of transaction's sender's address with expected address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrQortalPartnerAddress1, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrQortalPartnerAddress2, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrQortalPartnerAddress3, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrQortalPartnerAddress4, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check 'secret-A' in transaction's message */
+
+				// Extract secret-A from first 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageData (as pointed to by addrMessageDataPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageDataPointer));
+				// Load B register with expected hash result (as pointed to by addrHashOfSecretAPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.SET_B_IND, addrHashOfSecretAPointer));
+				// Perform HASH160 using source data at addrMessageData. (Location and length specified via addrMessageDataPointer and addrMessageDataLength).
+				// Save the equality result (1 if they match, 0 otherwise) into addrResult.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.CHECK_HASH160_WITH_B, addrResult, addrMessageDataPointer, addrMessageDataLength));
+				// If hashes don't match, addrResult will be zero so go find another transaction
+				codeByteBuffer.put(OpCode.BNZ_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelPayout)));
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Success! Pay arranged amount to receiving address */
+				labelPayout = codeByteBuffer.position();
+
+				// Extract Qortal receiving address from next 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrRedeemMessageReceivingAddressOffset));
+				// Save B register into data segment starting at addrPartnerReceivingAddress (as pointed to by addrPartnerReceivingAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerReceivingAddressPointer));
+				// Pay AT's balance to receiving address
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PAY_TO_ADDRESS_IN_B, addrQortAmount));
+				// Set redeemed mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REDEEMED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				// Fall-through to refunding any remaining balance back to AT creator
+
+				/* Refund balance back to AT creator */
+				labelRefund = codeByteBuffer.position();
+
+				// Set refunded mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REFUNDED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+			} catch (CompilationException e) {
+				throw new IllegalStateException("Unable to compile DGB-QORT ACCT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		assert Arrays.equals(Crypto.digest(codeBytes), DigibyteACCTv3.CODE_BYTES_HASH)
+			: String.format("BTCACCT.CODE_BYTES_HASH mismatch: expected %s, actual %s", HashCode.fromBytes(CODE_BYTES_HASH), HashCode.fromBytes(Crypto.digest(codeBytes)));
+
+		final short ciyamAtVersion = 2;
+		final short numCallStackPages = 0;
+		final short numUserStackPages = 0;
+		final long minActivationAmount = 0L;
+
+		return MachineState.toCreationBytes(ciyamAtVersion, codeBytes, dataByteBuffer.array(), numCallStackPages, numUserStackPages, minActivationAmount);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+		ATStateData atStateData = repository.getATRepository().getLatestATState(atData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atStateData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	public CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
+		byte[] addressBytes = new byte[25]; // for general use
+		String atAddress = atStateData.getATAddress();
+
+		CrossChainTradeData tradeData = new CrossChainTradeData();
+
+		tradeData.foreignBlockchain = SupportedBlockchain.DIGIBYTE.name();
+		tradeData.acctName = NAME;
+
+		tradeData.qortalAtAddress = atAddress;
+		tradeData.qortalCreator = Crypto.toAddress(creatorPublicKey);
+		tradeData.creationTimestamp = creationTimestamp;
+
+		Account atAccount = new Account(repository, atAddress);
+		tradeData.qortBalance = atAccount.getConfirmedBalance(Asset.QORT);
+
+		byte[] stateData = atStateData.getStateData();
+		ByteBuffer dataByteBuffer = ByteBuffer.wrap(stateData);
+		dataByteBuffer.position(MachineState.HEADER_LENGTH);
+
+		/* Constants */
+
+		// Skip creator's trade address
+		dataByteBuffer.get(addressBytes);
+		tradeData.qortalCreatorTradeAddress = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Creator's Digibyte/foreign public key hash
+		tradeData.creatorForeignPKH = new byte[20];
+		dataByteBuffer.get(tradeData.creatorForeignPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - tradeData.creatorForeignPKH.length); // skip to 32 bytes
+
+		// We don't use secret-B
+		tradeData.hashOfSecretB = null;
+
+		// Redeem payout
+		tradeData.qortAmount = dataByteBuffer.getLong();
+
+		// Expected DGB amount
+		tradeData.expectedForeignAmount = dataByteBuffer.getLong();
+
+		// Trade timeout
+		tradeData.tradeTimeout = (int) dataByteBuffer.getLong();
+
+		// Skip MESSAGE transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'trade' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'redeem' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Qortal trade address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for partner's Digibyte PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Digibyte PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'redeem' message data offset for partner's Qortal receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip message data length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		/* End of constants / begin variables */
+
+		// Skip AT creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Partner's trade address (if present)
+		dataByteBuffer.get(addressBytes);
+		String qortalRecipient = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Potential lockTimeA (if in trade mode)
+		int lockTimeA = (int) dataByteBuffer.getLong();
+
+		// AT refund timeout (probably only useful for debugging)
+		int refundTimeout = (int) dataByteBuffer.getLong();
+
+		// Trade-mode refund timestamp (AT 'timestamp' converted to Qortal block height)
+		long tradeRefundTimestamp = dataByteBuffer.getLong();
+
+		// Skip last transaction timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip block timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary result
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Skip message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Potential hash160 of secret A
+		byte[] hashOfSecretA = new byte[20];
+		dataByteBuffer.get(hashOfSecretA);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - hashOfSecretA.length); // skip to 32 bytes
+
+		// Potential partner's Digibyte PKH
+		byte[] partnerDigibytePKH = new byte[20];
+		dataByteBuffer.get(partnerDigibytePKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerDigibytePKH.length); // skip to 32 bytes
+
+		// Partner's receiving address (if present)
+		byte[] partnerReceivingAddress = new byte[25];
+		dataByteBuffer.get(partnerReceivingAddress);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerReceivingAddress.length); // skip to 32 bytes
+
+		// Trade AT's 'mode'
+		long modeValue = dataByteBuffer.getLong();
+		AcctMode mode = AcctMode.valueOf((int) (modeValue & 0xffL));
+
+		/* End of variables */
+
+		if (mode != null && mode != AcctMode.OFFERING) {
+			tradeData.mode = mode;
+			tradeData.refundTimeout = refundTimeout;
+			tradeData.tradeRefundHeight = new Timestamp(tradeRefundTimestamp).blockHeight;
+			tradeData.qortalPartnerAddress = qortalRecipient;
+			tradeData.hashOfSecretA = hashOfSecretA;
+			tradeData.partnerForeignPKH = partnerDigibytePKH;
+			tradeData.lockTimeA = lockTimeA;
+
+			if (mode == AcctMode.REDEEMED)
+				tradeData.qortalPartnerReceivingAddress = Base58.encode(partnerReceivingAddress);
+		} else {
+			tradeData.mode = AcctMode.OFFERING;
+		}
+
+		tradeData.duplicateDeprecated();
+
+		return tradeData;
+	}
+
+	/** Returns 'offer' MESSAGE payload for trade partner to send to AT creator's trade address. */
+	public static byte[] buildOfferMessage(byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA) {
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		return Bytes.concat(partnerBitcoinPKH, hashOfSecretA, lockTimeABytes);
+	}
+
+	/** Returns info extracted from 'offer' MESSAGE payload sent by trade partner to AT creator's trade address, or null if not valid. */
+	public static OfferMessageData extractOfferMessageData(byte[] messageData) {
+		if (messageData == null || messageData.length != OFFER_MESSAGE_LENGTH)
+			return null;
+
+		OfferMessageData offerMessageData = new OfferMessageData();
+		offerMessageData.partnerDigibytePKH = Arrays.copyOfRange(messageData, 0, 20);
+		offerMessageData.hashOfSecretA = Arrays.copyOfRange(messageData, 20, 40);
+		offerMessageData.lockTimeA = BitTwiddling.longFromBEBytes(messageData, 40);
+
+		return offerMessageData;
+	}
+
+	/** Returns 'trade' MESSAGE payload for AT creator to send to AT. */
+	public static byte[] buildTradeMessage(String partnerQortalTradeAddress, byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA, int refundTimeout) {
+		byte[] data = new byte[TRADE_MESSAGE_LENGTH];
+		byte[] partnerQortalAddressBytes = Base58.decode(partnerQortalTradeAddress);
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		byte[] refundTimeoutBytes = BitTwiddling.toBEByteArray((long) refundTimeout);
+
+		System.arraycopy(partnerQortalAddressBytes, 0, data, 0, partnerQortalAddressBytes.length);
+		System.arraycopy(partnerBitcoinPKH, 0, data, 32, partnerBitcoinPKH.length);
+		System.arraycopy(refundTimeoutBytes, 0, data, 56, refundTimeoutBytes.length);
+		System.arraycopy(hashOfSecretA, 0, data, 64, hashOfSecretA.length);
+		System.arraycopy(lockTimeABytes, 0, data, 88, lockTimeABytes.length);
+
+		return data;
+	}
+
+	/** Returns 'cancel' MESSAGE payload for AT creator to cancel trade AT. */
+	@Override
+	public byte[] buildCancelMessage(String creatorQortalAddress) {
+		byte[] data = new byte[CANCEL_MESSAGE_LENGTH];
+		byte[] creatorQortalAddressBytes = Base58.decode(creatorQortalAddress);
+
+		System.arraycopy(creatorQortalAddressBytes, 0, data, 0, creatorQortalAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns 'redeem' MESSAGE payload for trade partner to send to AT. */
+	public static byte[] buildRedeemMessage(byte[] secretA, String qortalReceivingAddress) {
+		byte[] data = new byte[REDEEM_MESSAGE_LENGTH];
+		byte[] qortalReceivingAddressBytes = Base58.decode(qortalReceivingAddress);
+
+		System.arraycopy(secretA, 0, data, 0, secretA.length);
+		System.arraycopy(qortalReceivingAddressBytes, 0, data, 32, qortalReceivingAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns refund timeout (minutes) based on trade partner's 'offer' MESSAGE timestamp and P2SH-A locktime. */
+	public static int calcRefundTimeout(long offerMessageTimestamp, int lockTimeA) {
+		// refund should be triggered halfway between offerMessageTimestamp and lockTimeA
+		return (int) ((lockTimeA - (offerMessageTimestamp / 1000L)) / 2L / 60L);
+	}
+
+	@Override
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+		String atAddress = crossChainTradeData.qortalAtAddress;
+		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
+
+		// We don't have partner's public key so we check every message to AT
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, atAddress, null, null, null);
+		if (messageTransactionsData == null)
+			return null;
+
+		// Find 'redeem' message
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			// Check message payload type/encryption
+			if (messageTransactionData.isText() || messageTransactionData.isEncrypted())
+				continue;
+
+			// Check message payload size
+			byte[] messageData = messageTransactionData.getData();
+			if (messageData.length != REDEEM_MESSAGE_LENGTH)
+				// Wrong payload length
+				continue;
+
+			// Check sender
+			if (!Crypto.toAddress(messageTransactionData.getSenderPublicKey()).equals(redeemerAddress))
+				// Wrong sender;
+				continue;
+
+			// Extract secretA
+			byte[] secretA = new byte[32];
+			System.arraycopy(messageData, 0, secretA, 0, secretA.length);
+
+			byte[] hashOfSecretA = Crypto.hash160(secretA);
+			if (!Arrays.equals(hashOfSecretA, crossChainTradeData.hashOfSecretA))
+				continue;
+
+			return secretA;
+		}
+
+		return null;
+	}
+
+}

src/main/java/org/qortal/crosschain/Ravencoin.java

@@ -0,0 +1,175 @@
+package org.qortal.crosschain;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.Map;
+
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.params.RegTestParams;
+import org.bitcoinj.params.TestNet3Params;
+import org.libdohj.params.RavencoinMainNetParams;
+import org.qortal.crosschain.ElectrumX.Server;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
+import org.qortal.settings.Settings;
+
+public class Ravencoin extends Bitcoiny {
+
+	public static final String CURRENCY_CODE = "RVN";
+
+	private static final Coin DEFAULT_FEE_PER_KB = Coin.valueOf(1125000); // 0.01125 RVN per 1000 bytes
+
+	private static final long MINIMUM_ORDER_AMOUNT = 1000000; // 0.01 RVN minimum order, to avoid dust errors
+
+	// Temporary values until a dynamic fee system is written.
+	private static final long MAINNET_FEE = 1000000L;
+	private static final long NON_MAINNET_FEE = 1000000L; // enough for TESTNET3 and should be OK for REGTEST
+
+	private static final Map<ConnectionType, Integer> DEFAULT_ELECTRUMX_PORTS = new EnumMap<>(ConnectionType.class);
+	static {
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.TCP, 50001);
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.SSL, 50002);
+	}
+
+	public enum RavencoinNet {
+		MAIN {
+			@Override
+			public NetworkParameters getParams() {
+				return RavencoinMainNetParams.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(
+						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=rvn
+						new Server("aethyn.com", ConnectionType.SSL, 50002),
+						new Server("electrum2.rvn.rocks", ConnectionType.SSL, 50002),
+						new Server("rvn-dashboard.com", ConnectionType.SSL, 50002),
+						new Server("rvn4lyfe.com", ConnectionType.SSL, 50002),
+						new Server("electrum1.cipig.net", ConnectionType.SSL, 20051),
+						new Server("electrum2.cipig.net", ConnectionType.SSL, 20051),
+						new Server("electrum3.cipig.net", ConnectionType.SSL, 20051));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "0000006b444bc2f2ffe627be9d9e7e7a0730000870ef6eb6da46c8eae389df90";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				// TODO: This will need to be replaced with something better in the near future!
+				return MAINNET_FEE;
+			}
+		},
+		TEST3 {
+			@Override
+			public NetworkParameters getParams() {
+				return TestNet3Params.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(); // TODO: find testnet servers
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "000000ecfc5e6324a079542221d00e10362bdc894d56500c414060eea8a3ad5a";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		},
+		REGTEST {
+			@Override
+			public NetworkParameters getParams() {
+				return RegTestParams.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(
+						new Server("localhost", ConnectionType.TCP, 50001),
+						new Server("localhost", ConnectionType.SSL, 50002));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				// This is unique to each regtest instance
+				return null;
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		};
+
+		public abstract NetworkParameters getParams();
+		public abstract Collection<Server> getServers();
+		public abstract String getGenesisHash();
+		public abstract long getP2shFee(Long timestamp) throws ForeignBlockchainException;
+	}
+
+	private static Ravencoin instance;
+
+	private final RavencoinNet ravencoinNet;
+
+	// Constructors and instance
+
+	private Ravencoin(RavencoinNet ravencoinNet, BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		super(blockchain, bitcoinjContext, currencyCode);
+		this.ravencoinNet = ravencoinNet;
+
+		LOGGER.info(() -> String.format("Starting Ravencoin support using %s", this.ravencoinNet.name()));
+	}
+
+	public static synchronized Ravencoin getInstance() {
+		if (instance == null) {
+			RavencoinNet ravencoinNet = Settings.getInstance().getRavencoinNet();
+
+			BitcoinyBlockchainProvider electrumX = new ElectrumX("Ravencoin-" + ravencoinNet.name(), ravencoinNet.getGenesisHash(), ravencoinNet.getServers(), DEFAULT_ELECTRUMX_PORTS);
+			Context bitcoinjContext = new Context(ravencoinNet.getParams());
+
+			instance = new Ravencoin(ravencoinNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+		}
+
+		return instance;
+	}
+
+	// Getters & setters
+
+	public static synchronized void resetForTesting() {
+		instance = null;
+	}
+
+	// Actual useful methods for use by other classes
+
+	@Override
+	public Coin getFeePerKb() {
+		return DEFAULT_FEE_PER_KB;
+	}
+
+	@Override
+	public long getMinimumOrderAmount() {
+		return MINIMUM_ORDER_AMOUNT;
+	}
+
+	/**
+	 * Returns estimated RVN fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes, or throws ForeignBlockchainException if something went wrong
+	 */
+	@Override
+	public long getP2shFee(Long timestamp) throws ForeignBlockchainException {
+		return this.ravencoinNet.getP2shFee(timestamp);
+	}
+
+}

src/main/java/org/qortal/crosschain/RavencoinACCTv3.java

@@ -0,0 +1,858 @@
+package org.qortal.crosschain;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.ciyam.at.*;
+import org.qortal.account.Account;
+import org.qortal.asset.Asset;
+import org.qortal.at.QortalFunctionCode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.utils.Base58;
+import org.qortal.utils.BitTwiddling;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.ciyam.at.OpCode.calcOffset;
+
+/**
+ * Cross-chain trade AT
+ * 
+ * <p>
+ * <ul>
+ * <li>Bob generates Ravencoin & Qortal 'trade' keys
+ * 		<ul>
+ * 			<li>private key required to sign P2SH redeem tx</li>
+ * 			<li>private key could be used to create 'secret' (e.g. double-SHA256)</li>
+ * 			<li>encrypted private key could be stored in Qortal AT for access by Bob from any node</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob deploys Qortal AT
+ * 		<ul>
+ * 		</ul>
+ * </li>
+ * <li>Alice finds Qortal AT and wants to trade
+ * 		<ul>
+ * 			<li>Alice generates Ravencoin & Qortal 'trade' keys</li>
+ * 			<li>Alice funds Ravencoin P2SH-A</li>
+ * 			<li>Alice sends 'offer' MESSAGE to Bob from her Qortal trade address, containing:
+ * 				<ul>
+ * 					<li>hash-of-secret-A</li>
+ * 					<li>her 'trade' Ravencoin PKH</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob receives "offer" MESSAGE
+ * 		<ul>
+ * 			<li>Checks Alice's P2SH-A</li>
+ * 			<li>Sends 'trade' MESSAGE to Qortal AT from his trade address, containing:
+ * 				<ul>
+ * 					<li>Alice's trade Qortal address</li>
+ * 					<li>Alice's trade Ravencoin PKH</li>
+ * 					<li>hash-of-secret-A</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Alice checks Qortal AT to confirm it's locked to her
+ * 		<ul>
+ * 			<li>Alice sends 'redeem' MESSAGE to Qortal AT from her trade address, containing:
+ * 				<ul>
+ * 					<li>secret-A</li>
+ * 					<li>Qortal receiving address of her chosing</li>
+ * 				</ul>
+ * 			</li>
+ * 			<li>AT's QORT funds are sent to Qortal receiving address</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob checks AT, extracts secret-A
+ * 		<ul>
+ * 			<li>Bob redeems P2SH-A using his Ravencoin trade key and secret-A</li>
+ * 			<li>P2SH-A RVN funds end up at Ravencoin address determined by redeem transaction output(s)</li>
+ * 		</ul>
+ * </li>
+ * </ul>
+ */
+public class RavencoinACCTv3 implements ACCT {
+
+	private static final Logger LOGGER = LogManager.getLogger(RavencoinACCTv3.class);
+
+	public static final String NAME = RavencoinACCTv3.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("91395fa1ec0dfa35beddb0a7f4cc0a1bede157c38787ddb0af0cf03dfdc10f77").asBytes(); // SHA256 of AT code bytes
+
+	public static final int SECRET_LENGTH = 32;
+
+	/** <b>Value</b> offset into AT segment where 'mode' variable (long) is stored. (Multiply by MachineState.VALUE_SIZE for byte offset). */
+	private static final int MODE_VALUE_OFFSET = 61;
+	/** <b>Byte</b> offset into AT state data where 'mode' variable (long) is stored. */
+	public static final int MODE_BYTE_OFFSET = MachineState.HEADER_LENGTH + (MODE_VALUE_OFFSET * MachineState.VALUE_SIZE);
+
+	public static class OfferMessageData {
+		public byte[] partnerRavencoinPKH;
+		public byte[] hashOfSecretA;
+		public long lockTimeA;
+	}
+	public static final int OFFER_MESSAGE_LENGTH = 20 /*partnerRavencoinPKH*/ + 20 /*hashOfSecretA*/ + 8 /*lockTimeA*/;
+	public static final int TRADE_MESSAGE_LENGTH = 32 /*partner's Qortal trade address (padded from 25 to 32)*/
+			+ 24 /*partner's Ravencoin PKH (padded from 20 to 24)*/
+			+ 8 /*AT trade timeout (minutes)*/
+			+ 24 /*hash of secret-A (padded from 20 to 24)*/
+			+ 8 /*lockTimeA*/;
+	public static final int REDEEM_MESSAGE_LENGTH = 32 /*secret-A*/ + 32 /*partner's Qortal receiving address padded from 25 to 32*/;
+	public static final int CANCEL_MESSAGE_LENGTH = 32 /*AT creator's Qortal address*/;
+
+	private static RavencoinACCTv3 instance;
+
+	private RavencoinACCTv3() {
+	}
+
+	public static synchronized RavencoinACCTv3 getInstance() {
+		if (instance == null)
+			instance = new RavencoinACCTv3();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Ravencoin.getInstance();
+	}
+
+	/**
+	 * Returns Qortal AT creation bytes for cross-chain trading AT.
+	 * <p>
+	 * <tt>tradeTimeout</tt> (minutes) is the time window for the trade partner to send the
+	 * 32-byte secret to the AT, before the AT automatically refunds the AT's creator.
+	 * 
+	 * @param creatorTradeAddress AT creator's trade Qortal address
+	 * @param ravencoinPublicKeyHash 20-byte HASH160 of creator's trade Ravencoin public key
+	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
+	 * @param ravencoinAmount how much RVN the AT creator is expecting to trade
+	 * @param tradeTimeout suggested timeout for entire trade
+	 */
+	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] ravencoinPublicKeyHash, long qortAmount, long ravencoinAmount, int tradeTimeout) {
+		if (ravencoinPublicKeyHash.length != 20)
+			throw new IllegalArgumentException("Ravencoin public key hash should be 20 bytes");
+
+		// Labels for data segment addresses
+		int addrCounter = 0;
+
+		// Constants (with corresponding dataByteBuffer.put*() calls below)
+
+		final int addrCreatorTradeAddress1 = addrCounter++;
+		final int addrCreatorTradeAddress2 = addrCounter++;
+		final int addrCreatorTradeAddress3 = addrCounter++;
+		final int addrCreatorTradeAddress4 = addrCounter++;
+
+		final int addrRavencoinPublicKeyHash = addrCounter;
+		addrCounter += 4;
+
+		final int addrQortAmount = addrCounter++;
+		final int addrRavencoinAmount = addrCounter++;
+		final int addrTradeTimeout = addrCounter++;
+
+		final int addrMessageTxnType = addrCounter++;
+		final int addrExpectedTradeMessageLength = addrCounter++;
+		final int addrExpectedRedeemMessageLength = addrCounter++;
+
+		final int addrCreatorAddressPointer = addrCounter++;
+		final int addrQortalPartnerAddressPointer = addrCounter++;
+		final int addrMessageSenderPointer = addrCounter++;
+
+		final int addrTradeMessagePartnerRavencoinPKHOffset = addrCounter++;
+		final int addrPartnerRavencoinPKHPointer = addrCounter++;
+		final int addrTradeMessageHashOfSecretAOffset = addrCounter++;
+		final int addrHashOfSecretAPointer = addrCounter++;
+
+		final int addrRedeemMessageReceivingAddressOffset = addrCounter++;
+
+		final int addrMessageDataPointer = addrCounter++;
+		final int addrMessageDataLength = addrCounter++;
+
+		final int addrPartnerReceivingAddressPointer = addrCounter++;
+
+		final int addrEndOfConstants = addrCounter;
+
+		// Variables
+
+		final int addrCreatorAddress1 = addrCounter++;
+		final int addrCreatorAddress2 = addrCounter++;
+		final int addrCreatorAddress3 = addrCounter++;
+		final int addrCreatorAddress4 = addrCounter++;
+
+		final int addrQortalPartnerAddress1 = addrCounter++;
+		final int addrQortalPartnerAddress2 = addrCounter++;
+		final int addrQortalPartnerAddress3 = addrCounter++;
+		final int addrQortalPartnerAddress4 = addrCounter++;
+
+		final int addrLockTimeA = addrCounter++;
+		final int addrRefundTimeout = addrCounter++;
+		final int addrRefundTimestamp = addrCounter++;
+		final int addrLastTxnTimestamp = addrCounter++;
+		final int addrBlockTimestamp = addrCounter++;
+		final int addrTxnType = addrCounter++;
+		final int addrResult = addrCounter++;
+
+		final int addrMessageSender1 = addrCounter++;
+		final int addrMessageSender2 = addrCounter++;
+		final int addrMessageSender3 = addrCounter++;
+		final int addrMessageSender4 = addrCounter++;
+
+		final int addrMessageLength = addrCounter++;
+
+		final int addrMessageData = addrCounter;
+		addrCounter += 4;
+
+		final int addrHashOfSecretA = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerRavencoinPKH = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerReceivingAddress = addrCounter;
+		addrCounter += 4;
+
+		final int addrMode = addrCounter++;
+		assert addrMode == MODE_VALUE_OFFSET : String.format("addrMode %d does not match MODE_VALUE_OFFSET %d", addrMode, MODE_VALUE_OFFSET);
+
+		// Data segment
+		ByteBuffer dataByteBuffer = ByteBuffer.allocate(addrCounter * MachineState.VALUE_SIZE);
+
+		// AT creator's trade Qortal address, decoded from Base58
+		assert dataByteBuffer.position() == addrCreatorTradeAddress1 * MachineState.VALUE_SIZE : "addrCreatorTradeAddress1 incorrect";
+		byte[] creatorTradeAddressBytes = Base58.decode(creatorTradeAddress);
+		dataByteBuffer.put(Bytes.ensureCapacity(creatorTradeAddressBytes, 32, 0));
+
+		// Ravencoin public key hash
+		assert dataByteBuffer.position() == addrRavencoinPublicKeyHash * MachineState.VALUE_SIZE : "addrRavencoinPublicKeyHash incorrect";
+		dataByteBuffer.put(Bytes.ensureCapacity(ravencoinPublicKeyHash, 32, 0));
+
+		// Redeem Qort amount
+		assert dataByteBuffer.position() == addrQortAmount * MachineState.VALUE_SIZE : "addrQortAmount incorrect";
+		dataByteBuffer.putLong(qortAmount);
+
+		// Expected Ravencoin amount
+		assert dataByteBuffer.position() == addrRavencoinAmount * MachineState.VALUE_SIZE : "addrRavencoinAmount incorrect";
+		dataByteBuffer.putLong(ravencoinAmount);
+
+		// Suggested trade timeout (minutes)
+		assert dataByteBuffer.position() == addrTradeTimeout * MachineState.VALUE_SIZE : "addrTradeTimeout incorrect";
+		dataByteBuffer.putLong(tradeTimeout);
+
+		// We're only interested in MESSAGE transactions
+		assert dataByteBuffer.position() == addrMessageTxnType * MachineState.VALUE_SIZE : "addrMessageTxnType incorrect";
+		dataByteBuffer.putLong(API.ATTransactionType.MESSAGE.value);
+
+		// Expected length of 'trade' MESSAGE data from AT creator
+		assert dataByteBuffer.position() == addrExpectedTradeMessageLength * MachineState.VALUE_SIZE : "addrExpectedTradeMessageLength incorrect";
+		dataByteBuffer.putLong(TRADE_MESSAGE_LENGTH);
+
+		// Expected length of 'redeem' MESSAGE data from trade partner
+		assert dataByteBuffer.position() == addrExpectedRedeemMessageLength * MachineState.VALUE_SIZE : "addrExpectedRedeemMessageLength incorrect";
+		dataByteBuffer.putLong(REDEEM_MESSAGE_LENGTH);
+
+		// Index into data segment of AT creator's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrCreatorAddressPointer * MachineState.VALUE_SIZE : "addrCreatorAddressPointer incorrect";
+		dataByteBuffer.putLong(addrCreatorAddress1);
+
+		// Index into data segment of partner's Qortal address, used by SET_B_IND
+		assert dataByteBuffer.position() == addrQortalPartnerAddressPointer * MachineState.VALUE_SIZE : "addrQortalPartnerAddressPointer incorrect";
+		dataByteBuffer.putLong(addrQortalPartnerAddress1);
+
+		// Index into data segment of (temporary) transaction's sender's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrMessageSenderPointer * MachineState.VALUE_SIZE : "addrMessageSenderPointer incorrect";
+		dataByteBuffer.putLong(addrMessageSender1);
+
+		// Offset into 'trade' MESSAGE data payload for extracting partner's Ravencoin PKH
+		assert dataByteBuffer.position() == addrTradeMessagePartnerRavencoinPKHOffset * MachineState.VALUE_SIZE : "addrTradeMessagePartnerRavencoinPKHOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Index into data segment of partner's Ravencoin PKH, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerRavencoinPKHPointer * MachineState.VALUE_SIZE : "addrPartnerRavencoinPKHPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerRavencoinPKH);
+
+		// Offset into 'trade' MESSAGE data payload for extracting hash-of-secret-A
+		assert dataByteBuffer.position() == addrTradeMessageHashOfSecretAOffset * MachineState.VALUE_SIZE : "addrTradeMessageHashOfSecretAOffset incorrect";
+		dataByteBuffer.putLong(64L);
+
+		// Index into data segment to hash of secret A, used by GET_B_IND
+		assert dataByteBuffer.position() == addrHashOfSecretAPointer * MachineState.VALUE_SIZE : "addrHashOfSecretAPointer incorrect";
+		dataByteBuffer.putLong(addrHashOfSecretA);
+
+		// Offset into 'redeem' MESSAGE data payload for extracting Qortal receiving address
+		assert dataByteBuffer.position() == addrRedeemMessageReceivingAddressOffset * MachineState.VALUE_SIZE : "addrRedeemMessageReceivingAddressOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Source location and length for hashing any passed secret
+		assert dataByteBuffer.position() == addrMessageDataPointer * MachineState.VALUE_SIZE : "addrMessageDataPointer incorrect";
+		dataByteBuffer.putLong(addrMessageData);
+		assert dataByteBuffer.position() == addrMessageDataLength * MachineState.VALUE_SIZE : "addrMessageDataLength incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Pointer into data segment of where to save partner's receiving Qortal address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerReceivingAddressPointer * MachineState.VALUE_SIZE : "addrPartnerReceivingAddressPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerReceivingAddress);
+
+		assert dataByteBuffer.position() == addrEndOfConstants * MachineState.VALUE_SIZE : "dataByteBuffer position not at end of constants";
+
+		// Code labels
+		Integer labelRefund = null;
+
+		Integer labelTradeTxnLoop = null;
+		Integer labelCheckTradeTxn = null;
+		Integer labelCheckCancelTxn = null;
+		Integer labelNotTradeNorCancelTxn = null;
+		Integer labelCheckNonRefundTradeTxn = null;
+		Integer labelTradeTxnExtract = null;
+		Integer labelRedeemTxnLoop = null;
+		Integer labelCheckRedeemTxn = null;
+		Integer labelCheckRedeemTxnSender = null;
+		Integer labelPayout = null;
+
+		ByteBuffer codeByteBuffer = ByteBuffer.allocate(768);
+
+		// Two-pass version
+		for (int pass = 0; pass < 2; ++pass) {
+			codeByteBuffer.clear();
+
+			try {
+				/* Initialization */
+
+				// Use AT creation 'timestamp' as starting point for finding transactions sent to AT
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_CREATION_TIMESTAMP, addrLastTxnTimestamp));
+
+				// Load B register with AT creator's address so we can save it into addrCreatorAddress1-4
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_CREATOR_INTO_B));
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrCreatorAddressPointer));
+
+				/* NOP - to ensure RAVENCOIN ACCT is unique */
+				codeByteBuffer.put(OpCode.NOP.compile());
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for message from AT creator's trade address containing trade partner details, or AT owner's address to cancel offer */
+
+				/* Transaction processing loop */
+				labelTradeTxnLoop = codeByteBuffer.position();
+
+				/* Sleep until message arrives */
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.SLEEP_UNTIL_MESSAGE.value, addrLastTxnTimestamp));
+
+				// Find next transaction (if any) to this AT since the last one (referenced by addrLastTxnTimestamp)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrResult to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckTradeTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckTradeTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelTradeTxnLoop)));
+
+				/* Check transaction's sender. We're expecting AT creator's trade address for 'trade' message, or AT creator's own address for 'cancel' message. */
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of message sender's address with AT creator's trade address. If they don't match, check for cancel situation.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorTradeAddress1, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorTradeAddress2, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorTradeAddress3, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorTradeAddress4, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				// Message sender's address matches AT creator's trade address so go process 'trade' message
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelCheckNonRefundTradeTxn == null ? 0 : labelCheckNonRefundTradeTxn));
+
+				/* Checking message sender for possible cancel message */
+				labelCheckCancelTxn = codeByteBuffer.position();
+
+				// Compare each part of message sender's address with AT creator's address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorAddress1, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorAddress2, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorAddress3, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorAddress4, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				// Partner address is AT creator's address, so cancel offer and finish.
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.CANCELLED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				/* Not trade nor cancel message */
+				labelNotTradeNorCancelTxn = codeByteBuffer.position();
+
+				// Loop to find another transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Possible switch-to-trade-mode message */
+				labelCheckNonRefundTradeTxn = codeByteBuffer.position();
+
+				// Check 'trade' message we received has expected number of message bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to info extraction code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedTradeMessageLength, calcOffset(codeByteBuffer, labelTradeTxnExtract)));
+				// Message length didn't match - go back to finding another 'trade' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Extracting info from 'trade' MESSAGE transaction */
+				labelTradeTxnExtract = codeByteBuffer.position();
+
+				// Extract message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrQortalPartnerAddress1 (as pointed to by addrQortalPartnerAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrQortalPartnerAddressPointer));
+
+				// Extract trade partner's Ravencoin public key hash (PKH) from message into B
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessagePartnerRavencoinPKHOffset));
+				// Store partner's Ravencoin PKH (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerRavencoinPKHPointer));
+				// Extract AT trade timeout (minutes) (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrRefundTimeout));
+
+				// Grab next 32 bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessageHashOfSecretAOffset));
+
+				// Extract hash-of-secret-A (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrHashOfSecretAPointer));
+				// Extract lockTime-A (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrLockTimeA));
+
+				// Calculate trade timeout refund 'timestamp' by adding addrRefundTimeout minutes to this transaction's 'timestamp', then save into addrRefundTimestamp
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.ADD_MINUTES_TO_TIMESTAMP, addrRefundTimestamp, addrLastTxnTimestamp, addrRefundTimeout));
+
+				/* We are in 'trade mode' */
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.TRADING.value));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for trade timeout or 'redeem' MESSAGE from Qortal trade partner */
+
+				// Fetch current block 'timestamp'
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_BLOCK_TIMESTAMP, addrBlockTimestamp));
+				// If we're not past refund 'timestamp' then look for next transaction
+				codeByteBuffer.put(OpCode.BLT_DAT.compile(addrBlockTimestamp, addrRefundTimestamp, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				// We're past refund 'timestamp' so go refund everything back to AT creator
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRefund == null ? 0 : labelRefund));
+
+				/* Transaction processing loop */
+				labelRedeemTxnLoop = codeByteBuffer.position();
+
+				// Find next transaction to this AT since the last one (if any)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrComparator to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckRedeemTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckRedeemTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check message payload length */
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to sender checking code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedRedeemMessageLength, calcOffset(codeByteBuffer, labelCheckRedeemTxnSender)));
+				// Message length didn't match - go back to finding another 'redeem' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Check transaction's sender */
+				labelCheckRedeemTxnSender = codeByteBuffer.position();
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of transaction's sender's address with expected address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrQortalPartnerAddress1, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrQortalPartnerAddress2, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrQortalPartnerAddress3, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrQortalPartnerAddress4, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check 'secret-A' in transaction's message */
+
+				// Extract secret-A from first 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageData (as pointed to by addrMessageDataPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageDataPointer));
+				// Load B register with expected hash result (as pointed to by addrHashOfSecretAPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.SET_B_IND, addrHashOfSecretAPointer));
+				// Perform HASH160 using source data at addrMessageData. (Location and length specified via addrMessageDataPointer and addrMessageDataLength).
+				// Save the equality result (1 if they match, 0 otherwise) into addrResult.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.CHECK_HASH160_WITH_B, addrResult, addrMessageDataPointer, addrMessageDataLength));
+				// If hashes don't match, addrResult will be zero so go find another transaction
+				codeByteBuffer.put(OpCode.BNZ_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelPayout)));
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Success! Pay arranged amount to receiving address */
+				labelPayout = codeByteBuffer.position();
+
+				// Extract Qortal receiving address from next 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrRedeemMessageReceivingAddressOffset));
+				// Save B register into data segment starting at addrPartnerReceivingAddress (as pointed to by addrPartnerReceivingAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerReceivingAddressPointer));
+				// Pay AT's balance to receiving address
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PAY_TO_ADDRESS_IN_B, addrQortAmount));
+				// Set redeemed mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REDEEMED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				// Fall-through to refunding any remaining balance back to AT creator
+
+				/* Refund balance back to AT creator */
+				labelRefund = codeByteBuffer.position();
+
+				// Set refunded mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REFUNDED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+			} catch (CompilationException e) {
+				throw new IllegalStateException("Unable to compile RVN-QORT ACCT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		assert Arrays.equals(Crypto.digest(codeBytes), RavencoinACCTv3.CODE_BYTES_HASH)
+			: String.format("BTCACCT.CODE_BYTES_HASH mismatch: expected %s, actual %s", HashCode.fromBytes(CODE_BYTES_HASH), HashCode.fromBytes(Crypto.digest(codeBytes)));
+
+		final short ciyamAtVersion = 2;
+		final short numCallStackPages = 0;
+		final short numUserStackPages = 0;
+		final long minActivationAmount = 0L;
+
+		return MachineState.toCreationBytes(ciyamAtVersion, codeBytes, dataByteBuffer.array(), numCallStackPages, numUserStackPages, minActivationAmount);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+		ATStateData atStateData = repository.getATRepository().getLatestATState(atData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atStateData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	public CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
+		byte[] addressBytes = new byte[25]; // for general use
+		String atAddress = atStateData.getATAddress();
+
+		CrossChainTradeData tradeData = new CrossChainTradeData();
+
+		tradeData.foreignBlockchain = SupportedBlockchain.RAVENCOIN.name();
+		tradeData.acctName = NAME;
+
+		tradeData.qortalAtAddress = atAddress;
+		tradeData.qortalCreator = Crypto.toAddress(creatorPublicKey);
+		tradeData.creationTimestamp = creationTimestamp;
+
+		Account atAccount = new Account(repository, atAddress);
+		tradeData.qortBalance = atAccount.getConfirmedBalance(Asset.QORT);
+
+		byte[] stateData = atStateData.getStateData();
+		ByteBuffer dataByteBuffer = ByteBuffer.wrap(stateData);
+		dataByteBuffer.position(MachineState.HEADER_LENGTH);
+
+		/* Constants */
+
+		// Skip creator's trade address
+		dataByteBuffer.get(addressBytes);
+		tradeData.qortalCreatorTradeAddress = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Creator's Ravencoin/foreign public key hash
+		tradeData.creatorForeignPKH = new byte[20];
+		dataByteBuffer.get(tradeData.creatorForeignPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - tradeData.creatorForeignPKH.length); // skip to 32 bytes
+
+		// We don't use secret-B
+		tradeData.hashOfSecretB = null;
+
+		// Redeem payout
+		tradeData.qortAmount = dataByteBuffer.getLong();
+
+		// Expected RVN amount
+		tradeData.expectedForeignAmount = dataByteBuffer.getLong();
+
+		// Trade timeout
+		tradeData.tradeTimeout = (int) dataByteBuffer.getLong();
+
+		// Skip MESSAGE transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'trade' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'redeem' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Qortal trade address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for partner's Ravencoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Ravencoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'redeem' message data offset for partner's Qortal receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip message data length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		/* End of constants / begin variables */
+
+		// Skip AT creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Partner's trade address (if present)
+		dataByteBuffer.get(addressBytes);
+		String qortalRecipient = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Potential lockTimeA (if in trade mode)
+		int lockTimeA = (int) dataByteBuffer.getLong();
+
+		// AT refund timeout (probably only useful for debugging)
+		int refundTimeout = (int) dataByteBuffer.getLong();
+
+		// Trade-mode refund timestamp (AT 'timestamp' converted to Qortal block height)
+		long tradeRefundTimestamp = dataByteBuffer.getLong();
+
+		// Skip last transaction timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip block timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary result
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Skip message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Potential hash160 of secret A
+		byte[] hashOfSecretA = new byte[20];
+		dataByteBuffer.get(hashOfSecretA);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - hashOfSecretA.length); // skip to 32 bytes
+
+		// Potential partner's Ravencoin PKH
+		byte[] partnerRavencoinPKH = new byte[20];
+		dataByteBuffer.get(partnerRavencoinPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerRavencoinPKH.length); // skip to 32 bytes
+
+		// Partner's receiving address (if present)
+		byte[] partnerReceivingAddress = new byte[25];
+		dataByteBuffer.get(partnerReceivingAddress);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerReceivingAddress.length); // skip to 32 bytes
+
+		// Trade AT's 'mode'
+		long modeValue = dataByteBuffer.getLong();
+		AcctMode mode = AcctMode.valueOf((int) (modeValue & 0xffL));
+
+		/* End of variables */
+
+		if (mode != null && mode != AcctMode.OFFERING) {
+			tradeData.mode = mode;
+			tradeData.refundTimeout = refundTimeout;
+			tradeData.tradeRefundHeight = new Timestamp(tradeRefundTimestamp).blockHeight;
+			tradeData.qortalPartnerAddress = qortalRecipient;
+			tradeData.hashOfSecretA = hashOfSecretA;
+			tradeData.partnerForeignPKH = partnerRavencoinPKH;
+			tradeData.lockTimeA = lockTimeA;
+
+			if (mode == AcctMode.REDEEMED)
+				tradeData.qortalPartnerReceivingAddress = Base58.encode(partnerReceivingAddress);
+		} else {
+			tradeData.mode = AcctMode.OFFERING;
+		}
+
+		tradeData.duplicateDeprecated();
+
+		return tradeData;
+	}
+
+	/** Returns 'offer' MESSAGE payload for trade partner to send to AT creator's trade address. */
+	public static byte[] buildOfferMessage(byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA) {
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		return Bytes.concat(partnerBitcoinPKH, hashOfSecretA, lockTimeABytes);
+	}
+
+	/** Returns info extracted from 'offer' MESSAGE payload sent by trade partner to AT creator's trade address, or null if not valid. */
+	public static OfferMessageData extractOfferMessageData(byte[] messageData) {
+		if (messageData == null || messageData.length != OFFER_MESSAGE_LENGTH)
+			return null;
+
+		OfferMessageData offerMessageData = new OfferMessageData();
+		offerMessageData.partnerRavencoinPKH = Arrays.copyOfRange(messageData, 0, 20);
+		offerMessageData.hashOfSecretA = Arrays.copyOfRange(messageData, 20, 40);
+		offerMessageData.lockTimeA = BitTwiddling.longFromBEBytes(messageData, 40);
+
+		return offerMessageData;
+	}
+
+	/** Returns 'trade' MESSAGE payload for AT creator to send to AT. */
+	public static byte[] buildTradeMessage(String partnerQortalTradeAddress, byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA, int refundTimeout) {
+		byte[] data = new byte[TRADE_MESSAGE_LENGTH];
+		byte[] partnerQortalAddressBytes = Base58.decode(partnerQortalTradeAddress);
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		byte[] refundTimeoutBytes = BitTwiddling.toBEByteArray((long) refundTimeout);
+
+		System.arraycopy(partnerQortalAddressBytes, 0, data, 0, partnerQortalAddressBytes.length);
+		System.arraycopy(partnerBitcoinPKH, 0, data, 32, partnerBitcoinPKH.length);
+		System.arraycopy(refundTimeoutBytes, 0, data, 56, refundTimeoutBytes.length);
+		System.arraycopy(hashOfSecretA, 0, data, 64, hashOfSecretA.length);
+		System.arraycopy(lockTimeABytes, 0, data, 88, lockTimeABytes.length);
+
+		return data;
+	}
+
+	/** Returns 'cancel' MESSAGE payload for AT creator to cancel trade AT. */
+	@Override
+	public byte[] buildCancelMessage(String creatorQortalAddress) {
+		byte[] data = new byte[CANCEL_MESSAGE_LENGTH];
+		byte[] creatorQortalAddressBytes = Base58.decode(creatorQortalAddress);
+
+		System.arraycopy(creatorQortalAddressBytes, 0, data, 0, creatorQortalAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns 'redeem' MESSAGE payload for trade partner to send to AT. */
+	public static byte[] buildRedeemMessage(byte[] secretA, String qortalReceivingAddress) {
+		byte[] data = new byte[REDEEM_MESSAGE_LENGTH];
+		byte[] qortalReceivingAddressBytes = Base58.decode(qortalReceivingAddress);
+
+		System.arraycopy(secretA, 0, data, 0, secretA.length);
+		System.arraycopy(qortalReceivingAddressBytes, 0, data, 32, qortalReceivingAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns refund timeout (minutes) based on trade partner's 'offer' MESSAGE timestamp and P2SH-A locktime. */
+	public static int calcRefundTimeout(long offerMessageTimestamp, int lockTimeA) {
+		// refund should be triggered halfway between offerMessageTimestamp and lockTimeA
+		return (int) ((lockTimeA - (offerMessageTimestamp / 1000L)) / 2L / 60L);
+	}
+
+	@Override
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+		String atAddress = crossChainTradeData.qortalAtAddress;
+		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
+
+		// We don't have partner's public key so we check every message to AT
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, atAddress, null, null, null);
+		if (messageTransactionsData == null)
+			return null;
+
+		// Find 'redeem' message
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			// Check message payload type/encryption
+			if (messageTransactionData.isText() || messageTransactionData.isEncrypted())
+				continue;
+
+			// Check message payload size
+			byte[] messageData = messageTransactionData.getData();
+			if (messageData.length != REDEEM_MESSAGE_LENGTH)
+				// Wrong payload length
+				continue;
+
+			// Check sender
+			if (!Crypto.toAddress(messageTransactionData.getSenderPublicKey()).equals(redeemerAddress))
+				// Wrong sender;
+				continue;
+
+			// Extract secretA
+			byte[] secretA = new byte[32];
+			System.arraycopy(messageData, 0, secretA, 0, secretA.length);
+
+			byte[] hashOfSecretA = Crypto.hash160(secretA);
+			if (!Arrays.equals(hashOfSecretA, crossChainTradeData.hashOfSecretA))
+				continue;
+
+			return secretA;
+		}
+
+		return null;
+	}
+
+}

src/main/java/org/qortal/crosschain/SupportedBlockchain.java

@@ -57,6 +57,34 @@ public enum SupportedBlockchain {
 		public ACCT getLatestAcct() {
 			return DogecoinACCTv3.getInstance();
 		}
+	},
+
+	DIGIBYTE(Arrays.asList(
+			Triple.valueOf(DigibyteACCTv3.NAME, DigibyteACCTv3.CODE_BYTES_HASH, DigibyteACCTv3::getInstance)
+		)) {
+		@Override
+		public ForeignBlockchain getInstance() {
+			return Digibyte.getInstance();
+		}
+
+		@Override
+		public ACCT getLatestAcct() {
+			return DigibyteACCTv3.getInstance();
+		}
+	},
+
+	RAVENCOIN(Arrays.asList(
+			Triple.valueOf(RavencoinACCTv3.NAME, RavencoinACCTv3.CODE_BYTES_HASH, RavencoinACCTv3::getInstance)
+		)) {
+		@Override
+		public ForeignBlockchain getInstance() {
+			return Ravencoin.getInstance();
+		}
+
+		@Override
+		public ACCT getLatestAcct() {
+			return RavencoinACCTv3.getInstance();
+		}
 	};
 
 	private static final Map<ByteArray, Supplier<ACCT>> supportedAcctsByCodeHash = Arrays.stream(SupportedBlockchain.values())

src/main/java/org/qortal/naming/Name.java

@@ -195,7 +195,7 @@ public class Name {
 		this.repository.getNameRepository().save(this.nameData);
 	}
 
-	public void buy(BuyNameTransactionData buyNameTransactionData) throws DataException {
+	public void buy(BuyNameTransactionData buyNameTransactionData, boolean modifyBalances) throws DataException {
 		// Save previous name-changing reference in this transaction's data
 		// Caller is expected to save
 		buyNameTransactionData.setNameReference(this.nameData.getReference());
@@ -203,15 +203,20 @@ public class Name {
 		// Mark not for-sale but leave price in case we want to orphan
 		this.nameData.setIsForSale(false);
 
-		// Update seller's balance
-		Account seller = new Account(this.repository, this.nameData.getOwner());
-		seller.modifyAssetBalance(Asset.QORT, buyNameTransactionData.getAmount());
+		if (modifyBalances) {
+			// Update seller's balance
+			Account seller = new Account(this.repository, this.nameData.getOwner());
+			seller.modifyAssetBalance(Asset.QORT, buyNameTransactionData.getAmount());
+		}
 
 		// Set new owner
 		Account buyer = new PublicKeyAccount(this.repository, buyNameTransactionData.getBuyerPublicKey());
 		this.nameData.setOwner(buyer.getAddress());
-		// Update buyer's balance
-		buyer.modifyAssetBalance(Asset.QORT, - buyNameTransactionData.getAmount());
+
+		if (modifyBalances) {
+			// Update buyer's balance
+			buyer.modifyAssetBalance(Asset.QORT, -buyNameTransactionData.getAmount());
+		}
 
 		// Set name-changing reference to this transaction
 		this.nameData.setReference(buyNameTransactionData.getSignature());

src/main/java/org/qortal/network/Handshake.java

@@ -13,7 +13,7 @@ import org.qortal.crypto.MemoryPoW;
 import org.qortal.network.message.ChallengeMessage;
 import org.qortal.network.message.HelloMessage;
 import org.qortal.network.message.Message;
-import org.qortal.network.message.Message.MessageType;
+import org.qortal.network.message.MessageType;
 import org.qortal.settings.Settings;
 import org.qortal.network.message.ResponseMessage;
 import org.qortal.utils.DaemonThreadFactory;

src/main/java/org/qortal/network/Network.java

@@ -13,6 +13,7 @@ import org.qortal.data.block.BlockData;
 import org.qortal.data.network.PeerData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.network.message.*;
+import org.qortal.network.task.*;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
@@ -32,6 +33,7 @@ import java.nio.channels.*;
 import java.security.SecureRandom;
 import java.util.*;
 import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Function;
@@ -41,9 +43,8 @@ import java.util.stream.Collectors;
 // For managing peers
 public class Network {
     private static final Logger LOGGER = LogManager.getLogger(Network.class);
-    private static Network instance;
 
-    private static final int LISTEN_BACKLOG = 10;
+    private static final int LISTEN_BACKLOG = 5;
     /**
      * How long before retrying after a connection failure, in milliseconds.
      */
@@ -122,14 +123,8 @@ public class Network {
     private final ExecuteProduceConsume networkEPC;
     private Selector channelSelector;
     private ServerSocketChannel serverChannel;
-    private Iterator<SelectionKey> channelIterator = null;
-
-    // volatile because value is updated inside any one of the EPC threads
-    private volatile long nextConnectTaskTimestamp = 0L; // ms - try first connect once NTP syncs
-
-    private final ExecutorService broadcastExecutor = Executors.newCachedThreadPool();
-    // volatile because value is updated inside any one of the EPC threads
-    private volatile long nextBroadcastTimestamp = 0L; // ms - try first broadcast once NTP syncs
+    private SelectionKey serverSelectionKey;
+    private final Set<SelectableChannel> channelsPendingWrite = ConcurrentHashMap.newKeySet();
 
     private final Lock mergePeersLock = new ReentrantLock();
 
@@ -137,6 +132,8 @@ public class Network {
     private String ourExternalIpAddress = null;
     private int ourExternalPort = Settings.getInstance().getListenPort();
 
+    private volatile boolean isShuttingDown = false;
+
     // Constructors
 
     private Network() {
@@ -170,7 +167,7 @@ public class Network {
             serverChannel.configureBlocking(false);
             serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
             serverChannel.bind(endpoint, LISTEN_BACKLOG);
-            serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
+            serverSelectionKey = serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
         } catch (UnknownHostException e) {
             LOGGER.error("Can't bind listen socket to address {}", Settings.getInstance().getBindAddress());
             throw new IOException("Can't bind listen socket to address", e);
@@ -180,7 +177,8 @@ public class Network {
         }
 
         // Load all known peers from repository
-        synchronized (this.allKnownPeers) { List<String> fixedNetwork = Settings.getInstance().getFixedNetwork();
+        synchronized (this.allKnownPeers) {
+            List<String> fixedNetwork = Settings.getInstance().getFixedNetwork();
             if (fixedNetwork != null && !fixedNetwork.isEmpty()) {
                 Long addedWhen = NTP.getTime();
                 String addedBy = "fixedNetwork";
@@ -214,12 +212,16 @@ public class Network {
 
     // Getters / setters
 
-    public static synchronized Network getInstance() {
-        if (instance == null) {
-            instance = new Network();
-        }
+    private static class SingletonContainer {
+        private static final Network INSTANCE = new Network();
+    }
 
-        return instance;
+    public static Network getInstance() {
+        return SingletonContainer.INSTANCE;
+    }
+
+    public int getMaxPeers() {
+        return this.maxPeers;
     }
 
     public byte[] getMessageMagic() {
@@ -453,6 +455,11 @@ public class Network {
 
     class NetworkProcessor extends ExecuteProduceConsume {
 
+        private final AtomicLong nextConnectTaskTimestamp = new AtomicLong(0L); // ms - try first connect once NTP syncs
+        private final AtomicLong nextBroadcastTimestamp = new AtomicLong(0L); // ms - try first broadcast once NTP syncs
+
+        private Iterator<SelectionKey> channelIterator = null;
+
         NetworkProcessor(ExecutorService executor) {
             super(executor);
         }
@@ -494,43 +501,23 @@ public class Network {
         }
 
         private Task maybeProducePeerMessageTask() {
-            for (Peer peer : getImmutableConnectedPeers()) {
-                Task peerTask = peer.getMessageTask();
-                if (peerTask != null) {
-                    return peerTask;
-                }
-            }
-
-            return null;
+            return getImmutableConnectedPeers().stream()
+                    .map(Peer::getMessageTask)
+                    .filter(Objects::nonNull)
+                    .findFirst()
+                    .orElse(null);
         }
 
         private Task maybeProducePeerPingTask(Long now) {
-            // Ask connected peers whether they need a ping
-            for (Peer peer : getImmutableHandshakedPeers()) {
-                Task peerTask = peer.getPingTask(now);
-                if (peerTask != null) {
-                    return peerTask;
-                }
-            }
-
-            return null;
-        }
-
-        class PeerConnectTask implements ExecuteProduceConsume.Task {
-            private final Peer peer;
-
-            PeerConnectTask(Peer peer) {
-                this.peer = peer;
-            }
-
-            @Override
-            public void perform() throws InterruptedException {
-                connectPeer(peer);
-            }
+            return getImmutableHandshakedPeers().stream()
+                    .map(peer -> peer.getPingTask(now))
+                    .filter(Objects::nonNull)
+                    .findFirst()
+                    .orElse(null);
         }
 
         private Task maybeProduceConnectPeerTask(Long now) throws InterruptedException {
-            if (now == null || now < nextConnectTaskTimestamp) {
+            if (now == null || now < nextConnectTaskTimestamp.get()) {
                 return null;
             }
 
@@ -538,7 +525,7 @@ public class Network {
                 return null;
             }
 
-            nextConnectTaskTimestamp = now + 1000L;
+            nextConnectTaskTimestamp.set(now + 1000L);
 
             Peer targetPeer = getConnectablePeer(now);
             if (targetPeer == null) {
@@ -550,66 +537,15 @@ public class Network {
         }
 
         private Task maybeProduceBroadcastTask(Long now) {
-            if (now == null || now < nextBroadcastTimestamp) {
+            if (now == null || now < nextBroadcastTimestamp.get()) {
                 return null;
             }
 
-            nextBroadcastTimestamp = now + BROADCAST_INTERVAL;
-            return () -> Controller.getInstance().doNetworkBroadcast();
-        }
-
-        class ChannelTask implements ExecuteProduceConsume.Task {
-            private final SelectionKey selectionKey;
-
-            ChannelTask(SelectionKey selectionKey) {
-                this.selectionKey = selectionKey;
-            }
-
-            @Override
-            public void perform() throws InterruptedException {
-                try {
-                    LOGGER.trace("Thread {} has pending channel: {}, with ops {}",
-                            Thread.currentThread().getId(), selectionKey.channel(), selectionKey.readyOps());
-
-                    // process pending channel task
-                    if (selectionKey.isReadable()) {
-                        connectionRead((SocketChannel) selectionKey.channel());
-                    } else if (selectionKey.isAcceptable()) {
-                        acceptConnection((ServerSocketChannel) selectionKey.channel());
-                    }
-
-                    LOGGER.trace("Thread {} processed channel: {}",
-                            Thread.currentThread().getId(), selectionKey.channel());
-                } catch (CancelledKeyException e) {
-                    LOGGER.trace("Thread {} encountered cancelled channel: {}",
-                            Thread.currentThread().getId(), selectionKey.channel());
-                }
-            }
-
-            private void connectionRead(SocketChannel socketChannel) {
-                Peer peer = getPeerFromChannel(socketChannel);
-                if (peer == null) {
-                    return;
-                }
-
-                try {
-                    peer.readChannel();
-                } catch (IOException e) {
-                    if (e.getMessage() != null && e.getMessage().toLowerCase().contains("connection reset")) {
-                        peer.disconnect("Connection reset");
-                        return;
-                    }
-
-                    LOGGER.trace("[{}] Network thread {} encountered I/O error: {}", peer.getPeerConnectionId(),
-                            Thread.currentThread().getId(), e.getMessage(), e);
-                    peer.disconnect("I/O error");
-                }
-            }
+            nextBroadcastTimestamp.set(now + BROADCAST_INTERVAL);
+            return new BroadcastTask();
         }
 
         private Task maybeProduceChannelTask(boolean canBlock) throws InterruptedException {
-            final SelectionKey nextSelectionKey;
-
             // Synchronization here to enforce thread-safety on channelIterator
             synchronized (channelSelector) {
                 // anything to do?
@@ -630,91 +566,73 @@ public class Network {
                     }
 
                     channelIterator = channelSelector.selectedKeys().iterator();
+                    LOGGER.trace("Thread {}, after {} select, channelIterator now {}",
+                            Thread.currentThread().getId(),
+                            canBlock ? "blocking": "non-blocking",
+                            channelIterator);
                 }
 
-                if (channelIterator.hasNext()) {
-                    nextSelectionKey = channelIterator.next();
-                    channelIterator.remove();
-                } else {
-                    nextSelectionKey = null;
+                if (!channelIterator.hasNext()) {
                     channelIterator = null; // Nothing to do so reset iterator to cause new select
+
+                    LOGGER.trace("Thread {}, channelIterator now null", Thread.currentThread().getId());
+                    return null;
                 }
 
-                LOGGER.trace("Thread {}, nextSelectionKey {}, channelIterator now {}",
-                        Thread.currentThread().getId(), nextSelectionKey, channelIterator);
-            }
+                final SelectionKey nextSelectionKey = channelIterator.next();
+                channelIterator.remove();
 
-            if (nextSelectionKey == null) {
-                return null;
-            }
+                // Just in case underlying socket channel already closed elsewhere, etc.
+                if (!nextSelectionKey.isValid())
+                    return null;
 
-            return new ChannelTask(nextSelectionKey);
-        }
-    }
+                LOGGER.trace("Thread {}, nextSelectionKey {}", Thread.currentThread().getId(), nextSelectionKey);
 
-    private void acceptConnection(ServerSocketChannel serverSocketChannel) throws InterruptedException {
-        SocketChannel socketChannel;
+                SelectableChannel socketChannel = nextSelectionKey.channel();
 
-        try {
-            socketChannel = serverSocketChannel.accept();
-        } catch (IOException e) {
-            return;
-        }
-
-        // No connection actually accepted?
-        if (socketChannel == null) {
-            return;
-        }
-        PeerAddress address = PeerAddress.fromSocket(socketChannel.socket());
-        List<String> fixedNetwork = Settings.getInstance().getFixedNetwork();
-        if (fixedNetwork != null && !fixedNetwork.isEmpty() && ipNotInFixedList(address, fixedNetwork)) {
-            try {
-                LOGGER.debug("Connection discarded from peer {} as not in the fixed network list", address);
-                socketChannel.close();
-            } catch (IOException e) {
-                // IGNORE
-            }
-            return;
-        }
-
-        final Long now = NTP.getTime();
-        Peer newPeer;
-
-        try {
-            if (now == null) {
-                LOGGER.debug("Connection discarded from peer {} due to lack of NTP sync", address);
-                socketChannel.close();
-                return;
-            }
-
-            if (getImmutableConnectedPeers().size() >= maxPeers) {
-                // We have enough peers
-                LOGGER.debug("Connection discarded from peer {} because the server is full", address);
-                socketChannel.close();
-                return;
-            }
-
-            LOGGER.debug("Connection accepted from peer {}", address);
-
-            newPeer = new Peer(socketChannel, channelSelector);
-            this.addConnectedPeer(newPeer);
-
-        } catch (IOException e) {
-            if (socketChannel.isOpen()) {
                 try {
-                    LOGGER.debug("Connection failed from peer {} while connecting/closing", address);
-                    socketChannel.close();
-                } catch (IOException ce) {
-                    // Couldn't close?
+                    if (nextSelectionKey.isReadable()) {
+                        clearInterestOps(nextSelectionKey, SelectionKey.OP_READ);
+                        Peer peer = getPeerFromChannel((SocketChannel) socketChannel);
+                        if (peer == null)
+                            return null;
+
+                        return new ChannelReadTask((SocketChannel) socketChannel, peer);
+                    }
+
+                    if (nextSelectionKey.isWritable()) {
+                        clearInterestOps(nextSelectionKey, SelectionKey.OP_WRITE);
+                        Peer peer = getPeerFromChannel((SocketChannel) socketChannel);
+                        if (peer == null)
+                            return null;
+
+                        // Any thread that queues a message to send can set OP_WRITE,
+                        // but we only allow one pending/active ChannelWriteTask per Peer
+                        if (!channelsPendingWrite.add(socketChannel))
+                            return null;
+
+                        return new ChannelWriteTask((SocketChannel) socketChannel, peer);
+                    }
+
+                    if (nextSelectionKey.isAcceptable()) {
+                        clearInterestOps(nextSelectionKey, SelectionKey.OP_ACCEPT);
+                        return new ChannelAcceptTask((ServerSocketChannel) socketChannel);
+                    }
+                } catch (CancelledKeyException e) {
+                    /*
+                     * Sometimes nextSelectionKey is cancelled / becomes invalid between the isValid() test at line 586
+                     * and later calls to isReadable() / isWritable() / isAcceptable() which themselves call isValid()!
+                     * Those isXXXable() calls could throw CancelledKeyException, so we catch it here and return null.
+                     */
+                    return null;
                 }
             }
-            return;
-        }
 
-        this.onPeerReady(newPeer);
+            return null;
+        }
     }
 
-    private boolean ipNotInFixedList(PeerAddress address, List<String> fixedNetwork) {
+    public boolean ipNotInFixedList(PeerAddress address, List<String> fixedNetwork) {
         for (String ipAddress : fixedNetwork) {
             String[] bits = ipAddress.split(":");
             if (bits.length >= 1 && bits.length <= 2 && address.getHost().equals(bits[0])) {
@@ -750,8 +668,9 @@ public class Network {
             peers.removeIf(isConnectedPeer);
 
             // Don't consider already connected peers (resolved address match)
-            // XXX This might be too slow if we end up waiting a long time for hostnames to resolve via DNS
-            peers.removeIf(isResolvedAsConnectedPeer);
+            // Disabled because this might be too slow if we end up waiting a long time for hostnames to resolve via DNS
+            // Which is ok because duplicate connections to the same peer are handled during handshaking
+            // peers.removeIf(isResolvedAsConnectedPeer);
 
             this.checkLongestConnection(now);
 
@@ -781,8 +700,12 @@ public class Network {
         }
     }
 
-    private boolean connectPeer(Peer newPeer) throws InterruptedException {
-        SocketChannel socketChannel = newPeer.connect(this.channelSelector);
+    public boolean connectPeer(Peer newPeer) throws InterruptedException {
+        // Also checked before creating PeerConnectTask
+        if (getImmutableOutboundHandshakedPeers().size() >= minOutboundPeers)
+            return false;
+
+        SocketChannel socketChannel = newPeer.connect();
         if (socketChannel == null) {
             return false;
         }
@@ -797,7 +720,7 @@ public class Network {
         return true;
     }
 
-    private Peer getPeerFromChannel(SocketChannel socketChannel) {
+    public Peer getPeerFromChannel(SocketChannel socketChannel) {
         for (Peer peer : this.getImmutableConnectedPeers()) {
             if (peer.getSocketChannel() == socketChannel) {
                 return peer;
@@ -830,7 +753,74 @@ public class Network {
         nextDisconnectionCheck = now + DISCONNECTION_CHECK_INTERVAL;
     }
 
-    // Peer callbacks
+    // SocketChannel interest-ops manipulations
+
+    private static final String[] OP_NAMES = new String[SelectionKey.OP_ACCEPT * 2];
+    static {
+        for (int i = 0; i < OP_NAMES.length; i++) {
+            StringJoiner joiner = new StringJoiner(",");
+
+            if ((i & SelectionKey.OP_READ) != 0) joiner.add("OP_READ");
+            if ((i & SelectionKey.OP_WRITE) != 0) joiner.add("OP_WRITE");
+            if ((i & SelectionKey.OP_CONNECT) != 0) joiner.add("OP_CONNECT");
+            if ((i & SelectionKey.OP_ACCEPT) != 0) joiner.add("OP_ACCEPT");
+
+            OP_NAMES[i] = joiner.toString();
+        }
+    }
+
+    public void clearInterestOps(SelectableChannel socketChannel, int interestOps) {
+        SelectionKey selectionKey = socketChannel.keyFor(channelSelector);
+        if (selectionKey == null)
+            return;
+
+        clearInterestOps(selectionKey, interestOps);
+    }
+
+    private void clearInterestOps(SelectionKey selectionKey, int interestOps) {
+        if (!selectionKey.channel().isOpen())
+            return;
+
+        LOGGER.trace("Thread {} clearing {} interest-ops on channel: {}",
+                Thread.currentThread().getId(),
+                OP_NAMES[interestOps],
+                selectionKey.channel());
+
+        selectionKey.interestOpsAnd(~interestOps);
+    }
+
+    public void setInterestOps(SelectableChannel socketChannel, int interestOps) {
+        SelectionKey selectionKey = socketChannel.keyFor(channelSelector);
+        if (selectionKey == null) {
+            try {
+                selectionKey = socketChannel.register(this.channelSelector, interestOps);
+            } catch (ClosedChannelException e) {
+                // Channel already closed so ignore
+                return;
+            }
+            // Fall-through to allow logging
+        }
+
+        setInterestOps(selectionKey, interestOps);
+    }
+
+    private void setInterestOps(SelectionKey selectionKey, int interestOps) {
+        if (!selectionKey.channel().isOpen())
+            return;
+
+        LOGGER.trace("Thread {} setting {} interest-ops on channel: {}",
+                Thread.currentThread().getId(),
+                OP_NAMES[interestOps],
+                selectionKey.channel());
+
+        selectionKey.interestOpsOr(interestOps);
+    }
+
+    // Peer / Task callbacks
+
+    public void notifyChannelNotWriting(SelectableChannel socketChannel) {
+        this.channelsPendingWrite.remove(socketChannel);
+    }
 
     protected void wakeupChannelSelector() {
         this.channelSelector.wakeup();
@@ -856,8 +846,6 @@ public class Network {
     }
 
     public void onDisconnect(Peer peer) {
-        // Notify Controller
-        Controller.getInstance().onPeerDisconnect(peer);
         if (peer.getConnectionEstablishedTime() > 0L) {
             LOGGER.debug("[{}] Disconnected from peer {}", peer.getPeerConnectionId(), peer);
         } else {
@@ -865,6 +853,25 @@ public class Network {
         }
 
         this.removeConnectedPeer(peer);
+        this.channelsPendingWrite.remove(peer.getSocketChannel());
+
+        if (this.isShuttingDown)
+            // No need to do any further processing, like re-enabling listen socket or notifying Controller
+            return;
+
+        if (getImmutableConnectedPeers().size() < maxPeers - 1
+                && serverSelectionKey.isValid()
+                && (serverSelectionKey.interestOps() & SelectionKey.OP_ACCEPT) == 0) {
+            try {
+                LOGGER.debug("Re-enabling accepting incoming connections because the server is not longer full");
+                setInterestOps(serverSelectionKey, SelectionKey.OP_ACCEPT);
+            } catch (CancelledKeyException e) {
+                LOGGER.error("Failed to re-enable accepting of incoming connections: {}", e.getMessage());
+            }
+        }
+
+        // Notify Controller
+        Controller.getInstance().onPeerDisconnect(peer);
     }
 
     public void peerMisbehaved(Peer peer) {
@@ -1302,8 +1309,9 @@ public class Network {
         try {
             InetSocketAddress knownAddress = peerAddress.toSocketAddress();
 
-            List<Peer> peers = this.getImmutableConnectedPeers();
-            peers.removeIf(peer -> !Peer.addressEquals(knownAddress, peer.getResolvedAddress()));
+            List<Peer> peers = this.getImmutableConnectedPeers().stream()
+                    .filter(peer -> Peer.addressEquals(knownAddress, peer.getResolvedAddress()))
+                    .collect(Collectors.toList());
 
             for (Peer peer : peers) {
                 peer.disconnect("to be forgotten");
@@ -1461,54 +1469,27 @@ public class Network {
     }
 
     public void broadcast(Function<Peer, Message> peerMessageBuilder) {
-        class Broadcaster implements Runnable {
-            private final Random random = new Random();
+        for (Peer peer : getImmutableHandshakedPeers()) {
+            if (this.isShuttingDown)
+                return;
 
-            private List<Peer> targetPeers;
-            private Function<Peer, Message> peerMessageBuilder;
+            Message message = peerMessageBuilder.apply(peer);
 
-            Broadcaster(List<Peer> targetPeers, Function<Peer, Message> peerMessageBuilder) {
-                this.targetPeers = targetPeers;
-                this.peerMessageBuilder = peerMessageBuilder;
+            if (message == null) {
+                continue;
             }
 
-            @Override
-            public void run() {
-                Thread.currentThread().setName("Network Broadcast");
-
-                for (Peer peer : targetPeers) {
-                    // Very short sleep to reduce strain, improve multi-threading and catch interrupts
-                    try {
-                        Thread.sleep(random.nextInt(20) + 20L);
-                    } catch (InterruptedException e) {
-                        break;
-                    }
-
-                    Message message = peerMessageBuilder.apply(peer);
-
-                    if (message == null) {
-                        continue;
-                    }
-
-                    if (!peer.sendMessage(message)) {
-                        peer.disconnect("failed to broadcast message");
-                    }
-                }
-
-                Thread.currentThread().setName("Network Broadcast (dormant)");
+            if (!peer.sendMessage(message)) {
+                peer.disconnect("failed to broadcast message");
             }
         }
-
-        try {
-            broadcastExecutor.execute(new Broadcaster(this.getImmutableHandshakedPeers(), peerMessageBuilder));
-        } catch (RejectedExecutionException e) {
-            // Can't execute - probably because we're shutting down, so ignore
-        }
     }
 
     // Shutdown
 
     public void shutdown() {
+        this.isShuttingDown = true;
+
         // Close listen socket to prevent more incoming connections
         if (this.serverChannel.isOpen()) {
             try {
@@ -1527,16 +1508,6 @@ public class Network {
             LOGGER.warn("Interrupted while waiting for networking threads to terminate");
         }
 
-        // Stop broadcasts
-        this.broadcastExecutor.shutdownNow();
-        try {
-            if (!this.broadcastExecutor.awaitTermination(1000, TimeUnit.MILLISECONDS)) {
-                LOGGER.warn("Broadcast threads failed to terminate");
-            }
-        } catch (InterruptedException e) {
-            LOGGER.warn("Interrupted while waiting for broadcast threads failed to terminate");
-        }
-
         // Close all peer connections
         for (Peer peer : this.getImmutableConnectedPeers()) {
             peer.shutdown();

src/main/java/org/qortal/network/Peer.java

@@ -11,25 +11,21 @@ import org.qortal.data.network.PeerChainTipData;
 import org.qortal.data.network.PeerData;
 import org.qortal.network.message.ChallengeMessage;
 import org.qortal.network.message.Message;
-import org.qortal.network.message.Message.MessageException;
-import org.qortal.network.message.Message.MessageType;
-import org.qortal.network.message.PingMessage;
+import org.qortal.network.message.MessageException;
+import org.qortal.network.task.MessageTask;
+import org.qortal.network.task.PingTask;
 import org.qortal.settings.Settings;
-import org.qortal.utils.ExecuteProduceConsume;
+import org.qortal.utils.ExecuteProduceConsume.Task;
 import org.qortal.utils.NTP;
 
 import java.io.IOException;
 import java.net.*;
 import java.nio.ByteBuffer;
 import java.nio.channels.SelectionKey;
-import java.nio.channels.Selector;
 import java.nio.channels.SocketChannel;
 import java.security.SecureRandom;
 import java.util.*;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -48,9 +44,9 @@ public class Peer {
     private static final int RESPONSE_TIMEOUT = 3000; // ms
 
     /**
-     * Maximum time to wait for a peer to respond with blocks (ms)
+     * Maximum time to wait for a message to be added to sendQueue (ms)
      */
-    public static final int FETCH_BLOCKS_TIMEOUT = 10000;
+    private static final int QUEUE_TIMEOUT = 1000; // ms
 
     /**
      * Interval between PING messages to a peer. (ms)
@@ -71,10 +67,14 @@ public class Peer {
     private final UUID peerConnectionId = UUID.randomUUID();
     private final Object byteBufferLock = new Object();
     private ByteBuffer byteBuffer;
-
     private Map<Integer, BlockingQueue<Message>> replyQueues;
     private LinkedBlockingQueue<Message> pendingMessages;
 
+    private TransferQueue<Message> sendQueue;
+    private ByteBuffer outputBuffer;
+    private String outputMessageType;
+    private int outputMessageId;
+
     /**
      * True if we created connection to peer, false if we accepted incoming connection from peer.
      */
@@ -98,7 +98,7 @@ public class Peer {
     /**
      * When last PING message was sent, or null if pings not started yet.
      */
-    private Long lastPingSent;
+    private Long lastPingSent = null;
 
     byte[] ourChallenge;
 
@@ -160,10 +160,10 @@ public class Peer {
     /**
      * Construct Peer using existing, connected socket
      */
-    public Peer(SocketChannel socketChannel, Selector channelSelector) throws IOException {
+    public Peer(SocketChannel socketChannel) throws IOException {
         this.isOutbound = false;
         this.socketChannel = socketChannel;
-        sharedSetup(channelSelector);
+        sharedSetup();
 
         this.resolvedAddress = ((InetSocketAddress) socketChannel.socket().getRemoteSocketAddress());
         this.isLocal = isAddressLocal(this.resolvedAddress.getAddress());
@@ -276,7 +276,7 @@ public class Peer {
         }
     }
 
-    protected void setLastPing(long lastPing) {
+    public void setLastPing(long lastPing) {
         synchronized (this.peerInfoLock) {
             this.lastPing = lastPing;
         }
@@ -346,12 +346,6 @@ public class Peer {
         }
     }
 
-    protected void queueMessage(Message message) {
-        if (!this.pendingMessages.offer(message)) {
-            LOGGER.info("[{}] No room to queue message from peer {} - discarding", this.peerConnectionId, this);
-        }
-    }
-
     public boolean isSyncInProgress() {
         return this.syncInProgress;
     }
@@ -396,13 +390,14 @@ public class Peer {
 
     // Processing
 
-    private void sharedSetup(Selector channelSelector) throws IOException {
+    private void sharedSetup() throws IOException {
         this.connectionTimestamp = NTP.getTime();
         this.socketChannel.setOption(StandardSocketOptions.TCP_NODELAY, true);
         this.socketChannel.configureBlocking(false);
-        this.socketChannel.register(channelSelector, SelectionKey.OP_READ);
+        Network.getInstance().setInterestOps(this.socketChannel, SelectionKey.OP_READ);
         this.byteBuffer = null; // Defer allocation to when we need it, to save memory. Sorry GC!
-        this.replyQueues = Collections.synchronizedMap(new HashMap<Integer, BlockingQueue<Message>>());
+        this.sendQueue = new LinkedTransferQueue<>();
+        this.replyQueues = new ConcurrentHashMap<>();
         this.pendingMessages = new LinkedBlockingQueue<>();
 
         Random random = new SecureRandom();
@@ -410,7 +405,7 @@ public class Peer {
         random.nextBytes(this.ourChallenge);
     }
 
-    public SocketChannel connect(Selector channelSelector) {
+    public SocketChannel connect() {
         LOGGER.trace("[{}] Connecting to peer {}", this.peerConnectionId, this);
 
         try {
@@ -418,6 +413,8 @@ public class Peer {
             this.isLocal = isAddressLocal(this.resolvedAddress.getAddress());
 
             this.socketChannel = SocketChannel.open();
+            InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+            this.socketChannel.socket().bind(new InetSocketAddress(bindAddr, 0));
             this.socketChannel.socket().connect(resolvedAddress, CONNECT_TIMEOUT);
         } catch (SocketTimeoutException e) {
             LOGGER.trace("[{}] Connection timed out to peer {}", this.peerConnectionId, this);
@@ -432,7 +429,7 @@ public class Peer {
 
         try {
             LOGGER.debug("[{}] Connected to peer {}", this.peerConnectionId, this);
-            sharedSetup(channelSelector);
+            sharedSetup();
             return socketChannel;
         } catch (IOException e) {
             LOGGER.trace("[{}] Post-connection setup failed, peer {}", this.peerConnectionId, this);
@@ -450,7 +447,7 @@ public class Peer {
      *
      * @throws IOException If this channel is not yet connected
      */
-    protected void readChannel() throws IOException {
+    public void readChannel() throws IOException {
         synchronized (this.byteBufferLock) {
             while (true) {
                 if (!this.socketChannel.isOpen() || this.socketChannel.socket().isClosed()) {
@@ -556,7 +553,67 @@ public class Peer {
         }
     }
 
-    protected ExecuteProduceConsume.Task getMessageTask() {
+    /** Maybe send some pending outgoing messages.
+     *
+     * @return true if more data is pending to be sent
+     */
+    public boolean writeChannel() throws IOException {
+        // It is the responsibility of ChannelWriteTask's producer to produce only one call to writeChannel() at a time
+
+        while (true) {
+            // If output byte buffer is null, fetch next message from queue (if any)
+            while (this.outputBuffer == null) {
+                Message message;
+
+                try {
+                    // Allow other thread time to add message to queue having raised OP_WRITE.
+                    // Timeout is overkill but not excessive enough to clog up networking / EPC.
+                    // This is to avoid race condition in sendMessageWithTimeout() below.
+                    message = this.sendQueue.poll(QUEUE_TIMEOUT, TimeUnit.MILLISECONDS);
+                } catch (InterruptedException e) {
+                    // Shutdown situation
+                    return false;
+                }
+
+                // No message? No further work to be done
+                if (message == null)
+                    return false;
+
+                try {
+                    this.outputBuffer = ByteBuffer.wrap(message.toBytes());
+                    this.outputMessageType = message.getType().name();
+                    this.outputMessageId = message.getId();
+
+                    LOGGER.trace("[{}] Sending {} message with ID {} to peer {}",
+                            this.peerConnectionId, this.outputMessageType, this.outputMessageId, this);
+                } catch (MessageException e) {
+                    // Something went wrong converting message to bytes, so discard but allow another round
+                    LOGGER.warn("[{}] Failed to send {} message with ID {} to peer {}: {}", this.peerConnectionId,
+                            message.getType().name(), message.getId(), this, e.getMessage());
+                }
+            }
+
+            // If output byte buffer is not null, send from that
+            int bytesWritten = this.socketChannel.write(outputBuffer);
+
+            LOGGER.trace("[{}] Sent {} bytes of {} message with ID {} to peer {} ({} total)", this.peerConnectionId,
+                    bytesWritten, this.outputMessageType, this.outputMessageId, this, outputBuffer.limit());
+
+            // If we've sent 0 bytes then socket buffer is full so we need to wait until it's empty again
+            if (bytesWritten == 0) {
+                return true;
+            }
+
+            // If we then exhaust the byte buffer, set it to null (otherwise loop and try to send more)
+            if (!this.outputBuffer.hasRemaining()) {
+                this.outputMessageType = null;
+                this.outputMessageId = 0;
+                this.outputBuffer = null;
+            }
+        }
+    }
+
+    protected Task getMessageTask() {
         /*
          * If we are still handshaking and there is a message yet to be processed then
          * don't produce another message task. This allows us to process handshake
@@ -580,7 +637,7 @@ public class Peer {
         }
 
         // Return a task to process message in queue
-        return () -> Network.getInstance().onMessage(this, nextMessage);
+        return new MessageTask(this, nextMessage);
     }
 
     /**
@@ -605,54 +662,25 @@ public class Peer {
         }
 
         try {
-            // Send message
-            LOGGER.trace("[{}] Sending {} message with ID {} to peer {}", this.peerConnectionId,
+            // Queue message, to be picked up by ChannelWriteTask and then peer.writeChannel()
+            LOGGER.trace("[{}] Queuing {} message with ID {} to peer {}", this.peerConnectionId,
                     message.getType().name(), message.getId(), this);
 
-            ByteBuffer outputBuffer = ByteBuffer.wrap(message.toBytes());
+            // Check message properly constructed
+            message.checkValidOutgoing();
 
-            synchronized (this.socketChannel) {
-                final long sendStart = System.currentTimeMillis();
-                long totalBytes = 0;
-
-                while (outputBuffer.hasRemaining()) {
-                    int bytesWritten = this.socketChannel.write(outputBuffer);
-                    totalBytes += bytesWritten;
-
-                    LOGGER.trace("[{}] Sent {} bytes of {} message with ID {} to peer {} ({} total)", this.peerConnectionId,
-                            bytesWritten, message.getType().name(), message.getId(), this, totalBytes);
-
-                    if (bytesWritten == 0) {
-                        // Underlying socket's internal buffer probably full,
-                        // so wait a short while for bytes to actually be transmitted over the wire
-
-                        /*
-                         * NOSONAR squid:S2276 - we don't want to use this.socketChannel.wait()
-                         * as this releases the lock held by synchronized() above
-                         * and would allow another thread to send another message,
-                         * potentially interleaving them on-the-wire, causing checksum failures
-                         * and connection loss.
-                         */
-                        Thread.sleep(1L); //NOSONAR squid:S2276
-
-                        if (System.currentTimeMillis() - sendStart > timeout) {
-                            // We've taken too long to send this message
-                            return false;
-                        }
-                    }
-                }
-            }
-        } catch (MessageException e) {
-            LOGGER.warn("[{}] Failed to send {} message with ID {} to peer {}: {}", this.peerConnectionId,
-                    message.getType().name(), message.getId(), this, e.getMessage());
-            return false;
-        } catch (IOException | InterruptedException e) {
+            // Possible race condition:
+            // We set OP_WRITE, EPC creates ChannelWriteTask which calls Peer.writeChannel, writeChannel's poll() finds no message to send
+            // Avoided by poll-with-timeout in writeChannel() above.
+            Network.getInstance().setInterestOps(this.socketChannel, SelectionKey.OP_WRITE);
+            return this.sendQueue.tryTransfer(message, timeout, TimeUnit.MILLISECONDS);
+        } catch (InterruptedException e) {
             // Send failure
             return false;
+        } catch (MessageException e) {
+            LOGGER.error(e.getMessage(), e);
+            return false;
         }
-
-        // Sent OK
-        return true;
     }
 
     /**
@@ -720,7 +748,7 @@ public class Peer {
         this.lastPingSent = NTP.getTime();
     }
 
-    protected ExecuteProduceConsume.Task getPingTask(Long now) {
+    protected Task getPingTask(Long now) {
         // Pings not enabled yet?
         if (now == null || this.lastPingSent == null) {
             return null;
@@ -734,19 +762,7 @@ public class Peer {
         // Not strictly true, but prevents this peer from being immediately chosen again
         this.lastPingSent = now;
 
-        return () -> {
-            PingMessage pingMessage = new PingMessage();
-            Message message = this.getResponse(pingMessage);
-
-            if (message == null || message.getType() != MessageType.PING) {
-                LOGGER.debug("[{}] Didn't receive reply from {} for PING ID {}", this.peerConnectionId, this,
-                        pingMessage.getId());
-                this.disconnect("no ping received");
-                return;
-            }
-
-            this.setLastPing(NTP.getTime() - now);
-        };
+        return new PingTask(this, now);
     }
 
     public void disconnect(String reason) {

src/main/java/org/qortal/network/message/ArbitraryDataFileListMessage.java

@@ -9,38 +9,59 @@ import org.qortal.utils.Serialization;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
 public class ArbitraryDataFileListMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-	private static final int HASH_LENGTH = Transformer.SHA256_LENGTH;
-	private static final int MAX_PEER_ADDRESS_LENGTH = PeerData.MAX_PEER_ADDRESS_SIZE;
-
-	private final byte[] signature;
-	private final List<byte[]> hashes;
+	private byte[] signature;
+	private List<byte[]> hashes;
 	private Long requestTime;
 	private Integer requestHops;
 	private String peerAddress;
 	private Boolean isRelayPossible;
 
-
 	public ArbitraryDataFileListMessage(byte[] signature, List<byte[]> hashes, Long requestTime,
-										Integer requestHops, String peerAddress, boolean isRelayPossible) {
+										Integer requestHops, String peerAddress, Boolean isRelayPossible) {
 		super(MessageType.ARBITRARY_DATA_FILE_LIST);
 
-		this.signature = signature;
-		this.hashes = hashes;
-		this.requestTime = requestTime;
-		this.requestHops = requestHops;
-		this.peerAddress = peerAddress;
-		this.isRelayPossible = isRelayPossible;
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Ints.toByteArray(hashes.size()));
+
+			for (byte[] hash : hashes) {
+				bytes.write(hash);
+			}
+
+			if (requestTime != null) {
+				// The remaining fields are optional
+
+				bytes.write(Longs.toByteArray(requestTime));
+
+				bytes.write(Ints.toByteArray(requestHops));
+
+				Serialization.serializeSizedStringV2(bytes, peerAddress);
+
+				bytes.write(Ints.toByteArray(Boolean.TRUE.equals(isRelayPossible) ? 1 : 0));
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
-	public ArbitraryDataFileListMessage(int id, byte[] signature, List<byte[]> hashes, Long requestTime,
+	/** Legacy version */
+	public ArbitraryDataFileListMessage(byte[] signature, List<byte[]> hashes) {
+		this(signature, hashes, null, null, null, null);
+	}
+
+	private ArbitraryDataFileListMessage(int id, byte[] signature, List<byte[]> hashes, Long requestTime,
 										Integer requestHops, String peerAddress, boolean isRelayPossible) {
 		super(id, MessageType.ARBITRARY_DATA_FILE_LIST);
 
@@ -52,24 +73,39 @@ public class ArbitraryDataFileListMessage extends Message {
 		this.isRelayPossible = isRelayPossible;
 	}
 
-	public List<byte[]> getHashes() {
-		return this.hashes;
-	}
-
 	public byte[] getSignature() {
 		return this.signature;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException, TransformationException {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public List<byte[]> getHashes() {
+		return this.hashes;
+	}
+
+	public Long getRequestTime() {
+		return this.requestTime;
+	}
+
+	public Integer getRequestHops() {
+		return this.requestHops;
+	}
+
+	public String getPeerAddress() {
+		return this.peerAddress;
+	}
+
+	public Boolean isRelayPossible() {
+		return this.isRelayPossible;
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws MessageException {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		bytes.get(signature);
 
 		int count = bytes.getInt();
 
 		List<byte[]> hashes = new ArrayList<>();
 		for (int i = 0; i < count; ++i) {
-
-			byte[] hash = new byte[HASH_LENGTH];
+			byte[] hash = new byte[Transformer.SHA256_LENGTH];
 			bytes.get(hash);
 			hashes.add(hash);
 		}
@@ -80,99 +116,21 @@ public class ArbitraryDataFileListMessage extends Message {
 		boolean isRelayPossible = true; // Legacy versions only send this message when relaying is possible
 
 		// The remaining fields are optional
-
 		if (bytes.hasRemaining()) {
+			try {
+				requestTime = bytes.getLong();
 
-			requestTime = bytes.getLong();
+				requestHops = bytes.getInt();
 
-			requestHops = bytes.getInt();
-
-			peerAddress = Serialization.deserializeSizedStringV2(bytes, MAX_PEER_ADDRESS_LENGTH);
-
-			isRelayPossible = bytes.getInt() > 0;
+				peerAddress = Serialization.deserializeSizedStringV2(bytes, PeerData.MAX_PEER_ADDRESS_SIZE);
 
+				isRelayPossible = bytes.getInt() > 0;
+			} catch (TransformationException e) {
+				throw new MessageException(e.getMessage(), e);
+			}
 		}
 
 		return new ArbitraryDataFileListMessage(id, signature, hashes, requestTime, requestHops, peerAddress, isRelayPossible);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			bytes.write(Ints.toByteArray(this.hashes.size()));
-
-			for (byte[] hash : this.hashes) {
-				bytes.write(hash);
-			}
-
-			if (this.requestTime == null) { // To maintain backwards support
-				return bytes.toByteArray();
-			}
-
-			// The remaining fields are optional
-
-			bytes.write(Longs.toByteArray(this.requestTime));
-
-			bytes.write(Ints.toByteArray(this.requestHops));
-
-			Serialization.serializeSizedStringV2(bytes, this.peerAddress);
-
-			bytes.write(Ints.toByteArray(this.isRelayPossible ? 1 : 0));
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
-	public ArbitraryDataFileListMessage cloneWithNewId(int newId) {
-		ArbitraryDataFileListMessage clone = new ArbitraryDataFileListMessage(this.signature, this.hashes,
-				this.requestTime, this.requestHops, this.peerAddress, this.isRelayPossible);
-		clone.setId(newId);
-		return clone;
-	}
-
-	public void removeOptionalStats() {
-		this.requestTime = null;
-		this.requestHops = null;
-		this.peerAddress = null;
-		this.isRelayPossible = null;
-	}
-
-	public Long getRequestTime() {
-		return this.requestTime;
-	}
-
-	public void setRequestTime(Long requestTime) {
-		this.requestTime = requestTime;
-	}
-
-	public Integer getRequestHops() {
-		return this.requestHops;
-	}
-
-	public void setRequestHops(Integer requestHops) {
-		this.requestHops = requestHops;
-	}
-
-	public String getPeerAddress() {
-		return this.peerAddress;
-	}
-
-	public void setPeerAddress(String peerAddress) {
-		this.peerAddress = peerAddress;
-	}
-
-	public Boolean isRelayPossible() {
-		return this.isRelayPossible;
-	}
-
-	public void setIsRelayPossible(Boolean isRelayPossible) {
-		this.isRelayPossible = isRelayPossible;
-	}
-
 }

src/main/java/org/qortal/network/message/ArbitraryDataFileMessage.java

@@ -9,44 +9,60 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 
 public class ArbitraryDataFileMessage extends Message {
 
 	private static final Logger LOGGER = LogManager.getLogger(ArbitraryDataFileMessage.class);
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
-	private final byte[] signature;
-	private final ArbitraryDataFile arbitraryDataFile;
+	private byte[] signature;
+	private ArbitraryDataFile arbitraryDataFile;
 
 	public ArbitraryDataFileMessage(byte[] signature, ArbitraryDataFile arbitraryDataFile) {
 		super(MessageType.ARBITRARY_DATA_FILE);
 
-		this.signature = signature;
-		this.arbitraryDataFile = arbitraryDataFile;
+		byte[] data = arbitraryDataFile.getBytes();
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Ints.toByteArray(data.length));
+
+			bytes.write(data);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
-	public ArbitraryDataFileMessage(int id, byte[] signature, ArbitraryDataFile arbitraryDataFile) {
+	private ArbitraryDataFileMessage(int id, byte[] signature, ArbitraryDataFile arbitraryDataFile) {
 		super(id, MessageType.ARBITRARY_DATA_FILE);
 
 		this.signature = signature;
 		this.arbitraryDataFile = arbitraryDataFile;
 	}
 
+	public byte[] getSignature() {
+		return this.signature;
+	}
+
 	public ArbitraryDataFile getArbitraryDataFile() {
 		return this.arbitraryDataFile;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		byteBuffer.get(signature);
 
 		int dataLength = byteBuffer.getInt();
 
-		if (byteBuffer.remaining() != dataLength)
-			return null;
+		if (byteBuffer.remaining() < dataLength)
+			throw new BufferUnderflowException();
 
 		byte[] data = new byte[dataLength];
 		byteBuffer.get(data);
@@ -54,43 +70,10 @@ public class ArbitraryDataFileMessage extends Message {
 		try {
 			ArbitraryDataFile arbitraryDataFile = new ArbitraryDataFile(data, signature);
 			return new ArbitraryDataFileMessage(id, signature, arbitraryDataFile);
-		}
-		catch (DataException e) {
+		} catch (DataException e) {
 			LOGGER.info("Unable to process received file: {}", e.getMessage());
-			return null;
+			throw new MessageException("Unable to process received file: " + e.getMessage(), e);
 		}
 	}
 
-	@Override
-	protected byte[] toData() {
-		if (this.arbitraryDataFile == null) {
-			return null;
-		}
-
-		byte[] data = this.arbitraryDataFile.getBytes();
-		if (data == null) {
-			return null;
-		}
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(signature);
-
-			bytes.write(Ints.toByteArray(data.length));
-
-			bytes.write(data);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
-	public ArbitraryDataFileMessage cloneWithNewId(int newId) {
-		ArbitraryDataFileMessage clone = new ArbitraryDataFileMessage(this.signature, this.arbitraryDataFile);
-		clone.setId(newId);
-		return clone;
-	}
-
 }

src/main/java/org/qortal/network/message/ArbitraryDataMessage.java

@@ -2,7 +2,7 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 
 import org.qortal.transform.Transformer;
@@ -11,13 +11,26 @@ import com.google.common.primitives.Ints;
 
 public class ArbitraryDataMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
 	private byte[] signature;
 	private byte[] data;
 
 	public ArbitraryDataMessage(byte[] signature, byte[] data) {
-		this(-1, signature, data);
+		super(MessageType.ARBITRARY_DATA);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Ints.toByteArray(data.length));
+
+			bytes.write(data);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private ArbitraryDataMessage(int id, byte[] signature, byte[] data) {
@@ -35,14 +48,14 @@ public class ArbitraryDataMessage extends Message {
 		return this.data;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		byteBuffer.get(signature);
 
 		int dataLength = byteBuffer.getInt();
 
-		if (byteBuffer.remaining() != dataLength)
-			return null;
+		if (byteBuffer.remaining() < dataLength)
+			throw new BufferUnderflowException();
 
 		byte[] data = new byte[dataLength];
 		byteBuffer.get(data);
@@ -50,24 +63,4 @@ public class ArbitraryDataMessage extends Message {
 		return new ArbitraryDataMessage(id, signature, data);
 	}
 
-	@Override
-	protected byte[] toData() {
-		if (this.data == null)
-			return null;
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			bytes.write(Ints.toByteArray(this.data.length));
-
-			bytes.write(this.data);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/ArbitraryMetadataMessage.java

@@ -7,28 +7,40 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 
 public class ArbitraryMetadataMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
+	private byte[] signature;
+	private ArbitraryDataFile arbitraryMetadataFile;
 
-	private final byte[] signature;
-	private final ArbitraryDataFile arbitraryMetadataFile;
-
-	public ArbitraryMetadataMessage(byte[] signature, ArbitraryDataFile arbitraryDataFile) {
+	public ArbitraryMetadataMessage(byte[] signature, ArbitraryDataFile arbitraryMetadataFile) {
 		super(MessageType.ARBITRARY_METADATA);
 
-		this.signature = signature;
-		this.arbitraryMetadataFile = arbitraryDataFile;
+		byte[] data = arbitraryMetadataFile.getBytes();
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Ints.toByteArray(data.length));
+
+			bytes.write(data);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
-	public ArbitraryMetadataMessage(int id, byte[] signature, ArbitraryDataFile arbitraryDataFile) {
+	private ArbitraryMetadataMessage(int id, byte[] signature, ArbitraryDataFile arbitraryMetadataFile) {
 		super(id, MessageType.ARBITRARY_METADATA);
 
 		this.signature = signature;
-		this.arbitraryMetadataFile = arbitraryDataFile;
+		this.arbitraryMetadataFile = arbitraryMetadataFile;
 	}
 
 	public byte[] getSignature() {
@@ -39,14 +51,14 @@ public class ArbitraryMetadataMessage extends Message {
 		return this.arbitraryMetadataFile;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		byteBuffer.get(signature);
 
 		int dataLength = byteBuffer.getInt();
 
-		if (byteBuffer.remaining() != dataLength)
-			return null;
+		if (byteBuffer.remaining() < dataLength)
+			throw new BufferUnderflowException();
 
 		byte[] data = new byte[dataLength];
 		byteBuffer.get(data);
@@ -54,42 +66,9 @@ public class ArbitraryMetadataMessage extends Message {
 		try {
 			ArbitraryDataFile arbitraryMetadataFile = new ArbitraryDataFile(data, signature);
 			return new ArbitraryMetadataMessage(id, signature, arbitraryMetadataFile);
+		} catch (DataException e) {
+			throw new MessageException("Unable to process arbitrary metadata message: " + e.getMessage(), e);
 		}
-		catch (DataException e) {
-			return null;
-		}
-	}
-
-	@Override
-	protected byte[] toData() {
-		if (this.arbitraryMetadataFile == null) {
-			return null;
-		}
-
-		byte[] data = this.arbitraryMetadataFile.getBytes();
-		if (data == null) {
-			return null;
-		}
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(signature);
-
-			bytes.write(Ints.toByteArray(data.length));
-
-			bytes.write(data);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
-	public ArbitraryMetadataMessage cloneWithNewId(int newId) {
-		ArbitraryMetadataMessage clone = new ArbitraryMetadataMessage(this.signature, this.arbitraryMetadataFile);
-		clone.setId(newId);
-		return clone;
 	}
 
 }

src/main/java/org/qortal/network/message/ArbitrarySignaturesMessage.java

@@ -8,21 +8,37 @@ import org.qortal.utils.Serialization;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
 public class ArbitrarySignaturesMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
 	private String peerAddress;
 	private int requestHops;
 	private List<byte[]> signatures;
 
 	public ArbitrarySignaturesMessage(String peerAddress, int requestHops, List<byte[]> signatures) {
-		this(-1, peerAddress, requestHops, signatures);
+		super(MessageType.ARBITRARY_SIGNATURES);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			Serialization.serializeSizedStringV2(bytes, peerAddress);
+
+			bytes.write(Ints.toByteArray(requestHops));
+
+			bytes.write(Ints.toByteArray(signatures.size()));
+
+			for (byte[] signature : signatures)
+				bytes.write(signature);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private ArbitrarySignaturesMessage(int id, String peerAddress, int requestHops, List<byte[]> signatures) {
@@ -41,27 +57,24 @@ public class ArbitrarySignaturesMessage extends Message {
 		return this.signatures;
 	}
 
-	public int getRequestHops() {
-		return this.requestHops;
-	}
-
-	public void setRequestHops(int requestHops) {
-		this.requestHops = requestHops;
-	}
-
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException, TransformationException {
-		String peerAddress = Serialization.deserializeSizedStringV2(bytes, PeerData.MAX_PEER_ADDRESS_SIZE);
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws MessageException {
+		String peerAddress;
+		try {
+			peerAddress = Serialization.deserializeSizedStringV2(bytes, PeerData.MAX_PEER_ADDRESS_SIZE);
+		} catch (TransformationException e) {
+			throw new MessageException(e.getMessage(), e);
+		}
 
 		int requestHops = bytes.getInt();
 
 		int signatureCount = bytes.getInt();
 
-		if (bytes.remaining() != signatureCount * SIGNATURE_LENGTH)
-			return null;
+		if (bytes.remaining() < signatureCount * Transformer.SIGNATURE_LENGTH)
+			throw new BufferUnderflowException();
 
 		List<byte[]> signatures = new ArrayList<>();
 		for (int i = 0; i < signatureCount; ++i) {
-			byte[] signature = new byte[SIGNATURE_LENGTH];
+			byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 			bytes.get(signature);
 			signatures.add(signature);
 		}
@@ -69,24 +82,4 @@ public class ArbitrarySignaturesMessage extends Message {
 		return new ArbitrarySignaturesMessage(id, peerAddress, requestHops, signatures);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			Serialization.serializeSizedStringV2(bytes, this.peerAddress);
-
-			bytes.write(Ints.toByteArray(this.requestHops));
-
-			bytes.write(Ints.toByteArray(this.signatures.size()));
-
-			for (byte[] signature : this.signatures)
-				bytes.write(signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/BlockMessage.java

@@ -1,14 +1,10 @@
 package org.qortal.network.message;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.List;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.qortal.block.Block;
 import org.qortal.data.at.ATStateData;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.transaction.TransactionData;
@@ -16,27 +12,15 @@ import org.qortal.transform.TransformationException;
 import org.qortal.transform.block.BlockTransformer;
 import org.qortal.utils.Triple;
 
-import com.google.common.primitives.Ints;
-
 public class BlockMessage extends Message {
 
 	private static final Logger LOGGER = LogManager.getLogger(BlockMessage.class);
 
-	private Block block = null;
+	private final BlockData blockData;
+	private final List<TransactionData> transactions;
+	private final List<ATStateData> atStates;
 
-	private BlockData blockData = null;
-	private List<TransactionData> transactions = null;
-	private List<ATStateData> atStates = null;
-
-	private int height;
-
-	public BlockMessage(Block block) {
-		super(MessageType.BLOCK);
-
-		this.block = block;
-		this.blockData = block.getBlockData();
-		this.height = block.getBlockData().getHeight();
-	}
+	// No public constructor as we're an incoming-only message type.
 
 	private BlockMessage(int id, BlockData blockData, List<TransactionData> transactions, List<ATStateData> atStates) {
 		super(id, MessageType.BLOCK);
@@ -44,8 +28,6 @@ public class BlockMessage extends Message {
 		this.blockData = blockData;
 		this.transactions = transactions;
 		this.atStates = atStates;
-
-		this.height = blockData.getHeight();
 	}
 
 	public BlockData getBlockData() {
@@ -60,7 +42,7 @@ public class BlockMessage extends Message {
 		return this.atStates;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
 		try {
 			int height = byteBuffer.getInt();
 
@@ -72,32 +54,8 @@ public class BlockMessage extends Message {
 			return new BlockMessage(id, blockData, blockInfo.getB(), blockInfo.getC());
 		} catch (TransformationException e) {
 			LOGGER.info(String.format("Received garbled BLOCK message: %s", e.getMessage()));
-			return null;
+			throw new MessageException(e.getMessage(), e);
 		}
 	}
 
-	@Override
-	protected byte[] toData() {
-		if (this.block == null)
-			return null;
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.height));
-
-			bytes.write(BlockTransformer.toBytes(this.block));
-
-			return bytes.toByteArray();
-		} catch (TransformationException | IOException e) {
-			return null;
-		}
-	}
-
-	public BlockMessage cloneWithNewId(int newId) {
-		BlockMessage clone = new BlockMessage(this.block);
-		clone.setId(newId);
-		return clone;
-	}
-
 }

src/main/java/org/qortal/network/message/BlockSummariesMessage.java

@@ -2,7 +2,7 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -20,7 +20,25 @@ public class BlockSummariesMessage extends Message {
 	private List<BlockSummaryData> blockSummaries;
 
 	public BlockSummariesMessage(List<BlockSummaryData> blockSummaries) {
-		this(-1, blockSummaries);
+		super(MessageType.BLOCK_SUMMARIES);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(blockSummaries.size()));
+
+			for (BlockSummaryData blockSummary : blockSummaries) {
+				bytes.write(Ints.toByteArray(blockSummary.getHeight()));
+				bytes.write(blockSummary.getSignature());
+				bytes.write(blockSummary.getMinterPublicKey());
+				bytes.write(Ints.toByteArray(blockSummary.getOnlineAccountsCount()));
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private BlockSummariesMessage(int id, List<BlockSummaryData> blockSummaries) {
@@ -33,11 +51,11 @@ public class BlockSummariesMessage extends Message {
 		return this.blockSummaries;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int count = bytes.getInt();
 
-		if (bytes.remaining() != count * BLOCK_SUMMARY_LENGTH)
-			return null;
+		if (bytes.remaining() < count * BLOCK_SUMMARY_LENGTH)
+			throw new BufferUnderflowException();
 
 		List<BlockSummaryData> blockSummaries = new ArrayList<>();
 		for (int i = 0; i < count; ++i) {
@@ -58,24 +76,4 @@ public class BlockSummariesMessage extends Message {
 		return new BlockSummariesMessage(id, blockSummaries);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.blockSummaries.size()));
-
-			for (BlockSummaryData blockSummary : this.blockSummaries) {
-				bytes.write(Ints.toByteArray(blockSummary.getHeight()));
-				bytes.write(blockSummary.getSignature());
-				bytes.write(blockSummary.getMinterPublicKey());
-				bytes.write(Ints.toByteArray(blockSummary.getOnlineAccountsCount()));
-			}
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/CachedBlockMessage.java

@@ -2,7 +2,6 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 import org.qortal.block.Block;
@@ -12,59 +11,34 @@ import org.qortal.transform.block.BlockTransformer;
 import com.google.common.primitives.Ints;
 
 // This is an OUTGOING-only Message which more readily lends itself to being cached
-public class CachedBlockMessage extends Message {
+public class CachedBlockMessage extends Message implements Cloneable {
 
-	private Block block = null;
-	private byte[] cachedBytes = null;
-
-	public CachedBlockMessage(Block block) {
+	public CachedBlockMessage(Block block) throws TransformationException {
 		super(MessageType.BLOCK);
 
-		this.block = block;
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(block.getBlockData().getHeight()));
+
+			bytes.write(BlockTransformer.toBytes(block));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	public CachedBlockMessage(byte[] cachedBytes) {
 		super(MessageType.BLOCK);
 
-		this.block = null;
-		this.cachedBytes = cachedBytes;
+		this.dataBytes = cachedBytes;
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
-	
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
+
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) {
 		throw new UnsupportedOperationException("CachedBlockMessage is for outgoing messages only");
 	}
 
-	@Override
-	protected byte[] toData() {
-		// Already serialized?
-		if (this.cachedBytes != null)
-			return cachedBytes;
-
-		if (this.block == null)
-			return null;
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.block.getBlockData().getHeight()));
-
-			bytes.write(BlockTransformer.toBytes(this.block));
-
-			this.cachedBytes = bytes.toByteArray();
-			// We no longer need source Block
-			// and Block contains repository handle which is highly likely to be invalid after this call
-			this.block = null;
-
-			return this.cachedBytes;
-		} catch (TransformationException | IOException e) {
-			return null;
-		}
-	}
-
-	public CachedBlockMessage cloneWithNewId(int newId) {
-		CachedBlockMessage clone = new CachedBlockMessage(this.cachedBytes);
-		clone.setId(newId);
-		return clone;
-	}
-
 }

src/main/java/org/qortal/network/message/ChallengeMessage.java

@@ -10,8 +10,25 @@ public class ChallengeMessage extends Message {
 
 	public static final int CHALLENGE_LENGTH = 32;
 
-	private final byte[] publicKey;
-	private final byte[] challenge;
+	private byte[] publicKey;
+	private byte[] challenge;
+
+	public ChallengeMessage(byte[] publicKey, byte[] challenge) {
+		super(MessageType.CHALLENGE);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(publicKey.length + challenge.length);
+
+		try {
+			bytes.write(publicKey);
+
+			bytes.write(challenge);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
 
 	private ChallengeMessage(int id, byte[] publicKey, byte[] challenge) {
 		super(id, MessageType.CHALLENGE);
@@ -20,10 +37,6 @@ public class ChallengeMessage extends Message {
 		this.challenge = challenge;
 	}
 
-	public ChallengeMessage(byte[] publicKey, byte[] challenge) {
-		this(-1, publicKey, challenge);
-	}
-
 	public byte[] getPublicKey() {
 		return this.publicKey;
 	}
@@ -42,15 +55,4 @@ public class ChallengeMessage extends Message {
 		return new ChallengeMessage(id, publicKey, challenge);
 	}
 
-	@Override
-	protected byte[] toData() throws IOException {
-		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-		bytes.write(this.publicKey);
-
-		bytes.write(this.challenge);
-
-		return bytes.toByteArray();
-	}
-
 }

src/main/java/org/qortal/network/message/GetArbitraryDataFileListMessage.java

@@ -5,33 +5,54 @@ import com.google.common.primitives.Longs;
 import org.qortal.data.network.PeerData;
 import org.qortal.transform.TransformationException;
 import org.qortal.transform.Transformer;
-import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.Serialization;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.qortal.transform.Transformer.INT_LENGTH;
-import static org.qortal.transform.Transformer.LONG_LENGTH;
-
 public class GetArbitraryDataFileListMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-	private static final int HASH_LENGTH = TransactionTransformer.SHA256_LENGTH;
-	private static final int MAX_PEER_ADDRESS_LENGTH = PeerData.MAX_PEER_ADDRESS_SIZE;
-
-	private final byte[] signature;
+	private byte[] signature;
 	private List<byte[]> hashes;
-	private final long requestTime;
+	private long requestTime;
 	private int requestHops;
 	private String requestingPeer;
 
 	public GetArbitraryDataFileListMessage(byte[] signature, List<byte[]> hashes, long requestTime, int requestHops, String requestingPeer) {
-		this(-1, signature, hashes, requestTime, requestHops, requestingPeer);
+		super(MessageType.GET_ARBITRARY_DATA_FILE_LIST);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Longs.toByteArray(requestTime));
+
+			bytes.write(Ints.toByteArray(requestHops));
+
+			if (hashes != null) {
+				bytes.write(Ints.toByteArray(hashes.size()));
+
+				for (byte[] hash : hashes) {
+					bytes.write(hash);
+				}
+			}
+			else {
+				bytes.write(Ints.toByteArray(0));
+			}
+
+			if (requestingPeer != null) {
+				Serialization.serializeSizedStringV2(bytes, requestingPeer);
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetArbitraryDataFileListMessage(int id, byte[] signature, List<byte[]> hashes, long requestTime, int requestHops, String requestingPeer) {
@@ -52,8 +73,20 @@ public class GetArbitraryDataFileListMessage extends Message {
 		return this.hashes;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException, TransformationException {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public long getRequestTime() {
+		return this.requestTime;
+	}
+
+	public int getRequestHops() {
+		return this.requestHops;
+	}
+
+	public String getRequestingPeer() {
+		return this.requestingPeer;
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws MessageException {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 
 		bytes.get(signature);
 
@@ -67,7 +100,7 @@ public class GetArbitraryDataFileListMessage extends Message {
 
 			hashes = new ArrayList<>();
 			for (int i = 0; i < hashCount; ++i) {
-				byte[] hash = new byte[HASH_LENGTH];
+				byte[] hash = new byte[Transformer.SHA256_LENGTH];
 				bytes.get(hash);
 				hashes.add(hash);
 			}
@@ -75,57 +108,14 @@ public class GetArbitraryDataFileListMessage extends Message {
 
 		String requestingPeer = null;
 		if (bytes.hasRemaining()) {
-			requestingPeer = Serialization.deserializeSizedStringV2(bytes, MAX_PEER_ADDRESS_LENGTH);
+			try {
+				requestingPeer = Serialization.deserializeSizedStringV2(bytes, PeerData.MAX_PEER_ADDRESS_SIZE);
+			} catch (TransformationException e) {
+				throw new MessageException(e.getMessage(), e);
+			}
 		}
 
 		return new GetArbitraryDataFileListMessage(id, signature, hashes, requestTime, requestHops, requestingPeer);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			bytes.write(Longs.toByteArray(this.requestTime));
-
-			bytes.write(Ints.toByteArray(this.requestHops));
-
-			if (this.hashes != null) {
-				bytes.write(Ints.toByteArray(this.hashes.size()));
-
-				for (byte[] hash : this.hashes) {
-					bytes.write(hash);
-				}
-			}
-			else {
-				bytes.write(Ints.toByteArray(0));
-			}
-
-			if (this.requestingPeer != null) {
-				Serialization.serializeSizedStringV2(bytes, this.requestingPeer);
-			}
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
-	public long getRequestTime() {
-		return this.requestTime;
-	}
-
-	public int getRequestHops() {
-		return this.requestHops;
-	}
-	public void setRequestHops(int requestHops) {
-		this.requestHops = requestHops;
-	}
-
-	public String getRequestingPeer() {
-		return this.requestingPeer;
-	}
-
 }

src/main/java/org/qortal/network/message/GetArbitraryDataFileMessage.java

@@ -1,23 +1,31 @@
 package org.qortal.network.message;
 
 import org.qortal.transform.Transformer;
-import org.qortal.transform.transaction.TransactionTransformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 public class GetArbitraryDataFileMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-	private static final int HASH_LENGTH = TransactionTransformer.SHA256_LENGTH;
-
-	private final byte[] signature;
-	private final byte[] hash;
+	private byte[] signature;
+	private byte[] hash;
 
 	public GetArbitraryDataFileMessage(byte[] signature, byte[] hash) {
-		this(-1, signature, hash);
+		super(MessageType.GET_ARBITRARY_DATA_FILE);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(signature.length + hash.length);
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(hash);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetArbitraryDataFileMessage(int id, byte[] signature, byte[] hash) {
@@ -35,32 +43,14 @@ public class GetArbitraryDataFileMessage extends Message {
 		return this.hash;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != HASH_LENGTH + SIGNATURE_LENGTH)
-			return null;
-
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		bytes.get(signature);
 
-		byte[] hash = new byte[HASH_LENGTH];
+		byte[] hash = new byte[Transformer.SHA256_LENGTH];
 		bytes.get(hash);
 
 		return new GetArbitraryDataFileMessage(id, signature, hash);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			bytes.write(this.hash);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetArbitraryDataMessage.java

@@ -1,20 +1,19 @@
 package org.qortal.network.message;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
+import java.util.Arrays;
 
 import org.qortal.transform.Transformer;
 
 public class GetArbitraryDataMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
 	private byte[] signature;
 
 	public GetArbitraryDataMessage(byte[] signature) {
-		this(-1, signature);
+		super(MessageType.GET_ARBITRARY_DATA);
+
+		this.dataBytes = Arrays.copyOf(signature, signature.length);
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetArbitraryDataMessage(int id, byte[] signature) {
@@ -27,28 +26,12 @@ public class GetArbitraryDataMessage extends Message {
 		return this.signature;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != SIGNATURE_LENGTH)
-			return null;
-
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 
 		bytes.get(signature);
 
 		return new GetArbitraryDataMessage(id, signature);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetArbitraryMetadataMessage.java

@@ -6,22 +6,31 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
-import static org.qortal.transform.Transformer.INT_LENGTH;
-import static org.qortal.transform.Transformer.LONG_LENGTH;
-
 public class GetArbitraryMetadataMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
-	private final byte[] signature;
-	private final long requestTime;
+	private byte[] signature;
+	private long requestTime;
 	private int requestHops;
 
 	public GetArbitraryMetadataMessage(byte[] signature, long requestTime, int requestHops) {
-		this(-1, signature, requestTime, requestHops);
+		super(MessageType.GET_ARBITRARY_METADATA);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(signature);
+
+			bytes.write(Longs.toByteArray(requestTime));
+
+			bytes.write(Ints.toByteArray(requestHops));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetArbitraryMetadataMessage(int id, byte[] signature, long requestTime, int requestHops) {
@@ -36,12 +45,16 @@ public class GetArbitraryMetadataMessage extends Message {
 		return this.signature;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != SIGNATURE_LENGTH + LONG_LENGTH + INT_LENGTH)
-			return null;
+	public long getRequestTime() {
+		return this.requestTime;
+	}
 
-		byte[] signature = new byte[SIGNATURE_LENGTH];
+	public int getRequestHops() {
+		return this.requestHops;
+	}
 
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 		bytes.get(signature);
 
 		long requestTime = bytes.getLong();
@@ -51,33 +64,4 @@ public class GetArbitraryMetadataMessage extends Message {
 		return new GetArbitraryMetadataMessage(id, signature, requestTime, requestHops);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			bytes.write(Longs.toByteArray(this.requestTime));
-
-			bytes.write(Ints.toByteArray(this.requestHops));
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
-	public long getRequestTime() {
-		return this.requestTime;
-	}
-
-	public int getRequestHops() {
-		return this.requestHops;
-	}
-
-	public void setRequestHops(int requestHops) {
-		this.requestHops = requestHops;
-	}
-
 }

src/main/java/org/qortal/network/message/GetBlockMessage.java

@@ -1,20 +1,19 @@
 package org.qortal.network.message;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
+import java.util.Arrays;
 
 import org.qortal.transform.block.BlockTransformer;
 
 public class GetBlockMessage extends Message {
 
-	private static final int BLOCK_SIGNATURE_LENGTH = BlockTransformer.BLOCK_SIGNATURE_LENGTH;
-
 	private byte[] signature;
 
 	public GetBlockMessage(byte[] signature) {
-		this(-1, signature);
+		super(MessageType.GET_BLOCK);
+
+		this.dataBytes = Arrays.copyOf(signature, signature.length);
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetBlockMessage(int id, byte[] signature) {
@@ -27,28 +26,11 @@ public class GetBlockMessage extends Message {
 		return this.signature;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != BLOCK_SIGNATURE_LENGTH)
-			return null;
-
-		byte[] signature = new byte[BLOCK_SIGNATURE_LENGTH];
-
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] signature = new byte[BlockTransformer.BLOCK_SIGNATURE_LENGTH];
 		bytes.get(signature);
 
 		return new GetBlockMessage(id, signature);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetBlockSummariesMessage.java

@@ -2,23 +2,32 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
-import org.qortal.transform.Transformer;
 import org.qortal.transform.block.BlockTransformer;
 
 import com.google.common.primitives.Ints;
 
 public class GetBlockSummariesMessage extends Message {
 
-	private static final int BLOCK_SIGNATURE_LENGTH = BlockTransformer.BLOCK_SIGNATURE_LENGTH;
-
 	private byte[] parentSignature;
 	private int numberRequested;
 
 	public GetBlockSummariesMessage(byte[] parentSignature, int numberRequested) {
-		this(-1, parentSignature, numberRequested);
+		super(MessageType.GET_BLOCK_SUMMARIES);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(parentSignature);
+
+			bytes.write(Ints.toByteArray(numberRequested));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetBlockSummariesMessage(int id, byte[] parentSignature, int numberRequested) {
@@ -36,11 +45,8 @@ public class GetBlockSummariesMessage extends Message {
 		return this.numberRequested;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != BLOCK_SIGNATURE_LENGTH + Transformer.INT_LENGTH)
-			return null;
-
-		byte[] parentSignature = new byte[BLOCK_SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] parentSignature = new byte[BlockTransformer.BLOCK_SIGNATURE_LENGTH];
 		bytes.get(parentSignature);
 
 		int numberRequested = bytes.getInt();
@@ -48,19 +54,4 @@ public class GetBlockSummariesMessage extends Message {
 		return new GetBlockSummariesMessage(id, parentSignature, numberRequested);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.parentSignature);
-
-			bytes.write(Ints.toByteArray(this.numberRequested));
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetOnlineAccountsMessage.java

@@ -2,7 +2,6 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -20,7 +19,24 @@ public class GetOnlineAccountsMessage extends Message {
 	private List<OnlineAccountData> onlineAccounts;
 
 	public GetOnlineAccountsMessage(List<OnlineAccountData> onlineAccounts) {
-		this(-1, onlineAccounts);
+		super(MessageType.GET_ONLINE_ACCOUNTS);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(onlineAccounts.size()));
+
+			for (OnlineAccountData onlineAccountData : onlineAccounts) {
+				bytes.write(Longs.toByteArray(onlineAccountData.getTimestamp()));
+
+				bytes.write(onlineAccountData.getPublicKey());
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetOnlineAccountsMessage(int id, List<OnlineAccountData> onlineAccounts) {
@@ -33,7 +49,7 @@ public class GetOnlineAccountsMessage extends Message {
 		return this.onlineAccounts;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		final int accountCount = bytes.getInt();
 
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
@@ -50,24 +66,4 @@ public class GetOnlineAccountsMessage extends Message {
 		return new GetOnlineAccountsMessage(id, onlineAccounts);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.onlineAccounts.size()));
-
-			for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-				OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-				bytes.write(Longs.toByteArray(onlineAccountData.getTimestamp()));
-
-				bytes.write(onlineAccountData.getPublicKey());
-			}
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetOnlineAccountsV2Message.java

@@ -7,7 +7,6 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -24,11 +23,51 @@ import java.util.Map;
  * Also V2 only builds online accounts message once!
  */
 public class GetOnlineAccountsV2Message extends Message {
+
 	private List<OnlineAccountData> onlineAccounts;
-	private byte[] cachedData;
 
 	public GetOnlineAccountsV2Message(List<OnlineAccountData> onlineAccounts) {
-		this(-1, onlineAccounts);
+		super(MessageType.GET_ONLINE_ACCOUNTS_V2);
+
+		// If we don't have ANY online accounts then it's an easier construction...
+		if (onlineAccounts.isEmpty()) {
+			// Always supply a number of accounts
+			this.dataBytes = Ints.toByteArray(0);
+			this.checksumBytes = Message.generateChecksum(this.dataBytes);
+			return;
+		}
+
+		// How many of each timestamp
+		Map<Long, Integer> countByTimestamp = new HashMap<>();
+
+		for (OnlineAccountData onlineAccountData : onlineAccounts) {
+			Long timestamp = onlineAccountData.getTimestamp();
+			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
+		}
+
+		// We should know exactly how many bytes to allocate now
+		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
+				+ onlineAccounts.size() * Transformer.PUBLIC_KEY_LENGTH;
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
+
+		try {
+			for (long timestamp : countByTimestamp.keySet()) {
+				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
+
+				bytes.write(Longs.toByteArray(timestamp));
+
+				for (OnlineAccountData onlineAccountData : onlineAccounts) {
+					if (onlineAccountData.getTimestamp() == timestamp)
+						bytes.write(onlineAccountData.getPublicKey());
+				}
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetOnlineAccountsV2Message(int id, List<OnlineAccountData> onlineAccounts) {
@@ -41,7 +80,7 @@ public class GetOnlineAccountsV2Message extends Message {
 		return this.onlineAccounts;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int accountCount = bytes.getInt();
 
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
@@ -67,51 +106,4 @@ public class GetOnlineAccountsV2Message extends Message {
 		return new GetOnlineAccountsV2Message(id, onlineAccounts);
 	}
 
-	@Override
-	protected synchronized byte[] toData() {
-		if (this.cachedData != null)
-			return this.cachedData;
-
-		// Shortcut in case we have no online accounts
-		if (this.onlineAccounts.isEmpty()) {
-			this.cachedData = Ints.toByteArray(0);
-			return this.cachedData;
-		}
-
-		// How many of each timestamp
-		Map<Long, Integer> countByTimestamp = new HashMap<>();
-
-		for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-			OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-			Long timestamp = onlineAccountData.getTimestamp();
-			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
-		}
-
-		// We should know exactly how many bytes to allocate now
-		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
-				+ this.onlineAccounts.size() * Transformer.PUBLIC_KEY_LENGTH;
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
-
-			for (long timestamp : countByTimestamp.keySet()) {
-				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
-
-				bytes.write(Longs.toByteArray(timestamp));
-
-				for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-					OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-
-					if (onlineAccountData.getTimestamp() == timestamp)
-						bytes.write(onlineAccountData.getPublicKey());
-				}
-			}
-
-			this.cachedData = bytes.toByteArray();
-			return this.cachedData;
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetPeersMessage.java

@@ -1,25 +1,21 @@
 package org.qortal.network.message;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 public class GetPeersMessage extends Message {
 
 	public GetPeersMessage() {
-		this(-1);
+		super(MessageType.GET_PEERS);
+
+		this.dataBytes = EMPTY_DATA_BYTES;
 	}
 
 	private GetPeersMessage(int id) {
 		super(id, MessageType.GET_PEERS);
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		return new GetPeersMessage(id);
 	}
 
-	@Override
-	protected byte[] toData() {
-		return new byte[0];
-	}
-
 }

src/main/java/org/qortal/network/message/GetSignaturesV2Message.java

@@ -2,24 +2,32 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
-import org.qortal.transform.Transformer;
 import org.qortal.transform.block.BlockTransformer;
 
 import com.google.common.primitives.Ints;
 
 public class GetSignaturesV2Message extends Message {
 
-	private static final int BLOCK_SIGNATURE_LENGTH = BlockTransformer.BLOCK_SIGNATURE_LENGTH;
-	private static final int NUMBER_REQUESTED_LENGTH = Transformer.INT_LENGTH;
-
 	private byte[] parentSignature;
 	private int numberRequested;
 
 	public GetSignaturesV2Message(byte[] parentSignature, int numberRequested) {
-		this(-1, parentSignature, numberRequested);
+		super(MessageType.GET_SIGNATURES_V2);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(parentSignature);
+
+			bytes.write(Ints.toByteArray(numberRequested));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetSignaturesV2Message(int id, byte[] parentSignature, int numberRequested) {
@@ -37,11 +45,8 @@ public class GetSignaturesV2Message extends Message {
 		return this.numberRequested;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != BLOCK_SIGNATURE_LENGTH + NUMBER_REQUESTED_LENGTH)
-			return null;
-
-		byte[] parentSignature = new byte[BLOCK_SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] parentSignature = new byte[BlockTransformer.BLOCK_SIGNATURE_LENGTH];
 		bytes.get(parentSignature);
 
 		int numberRequested = bytes.getInt();
@@ -49,19 +54,4 @@ public class GetSignaturesV2Message extends Message {
 		return new GetSignaturesV2Message(id, parentSignature, numberRequested);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.parentSignature);
-
-			bytes.write(Ints.toByteArray(this.numberRequested));
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetTradePresencesMessage.java

@@ -7,7 +7,6 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -21,10 +20,48 @@ import java.util.Map;
  */
 public class GetTradePresencesMessage extends Message {
 	private List<TradePresenceData> tradePresences;
-	private byte[] cachedData;
 
 	public GetTradePresencesMessage(List<TradePresenceData> tradePresences) {
-		this(-1, tradePresences);
+		super(MessageType.GET_TRADE_PRESENCES);
+
+		// Shortcut in case we have no trade presences
+		if (tradePresences.isEmpty()) {
+			this.dataBytes = Ints.toByteArray(0);
+			this.checksumBytes = Message.generateChecksum(this.dataBytes);
+			return;
+		}
+
+		// How many of each timestamp
+		Map<Long, Integer> countByTimestamp = new HashMap<>();
+
+		for (TradePresenceData tradePresenceData : tradePresences) {
+			Long timestamp = tradePresenceData.getTimestamp();
+			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
+		}
+
+		// We should know exactly how many bytes to allocate now
+		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
+				+ tradePresences.size() * Transformer.PUBLIC_KEY_LENGTH;
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
+
+		try {
+			for (long timestamp : countByTimestamp.keySet()) {
+				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
+
+				bytes.write(Longs.toByteArray(timestamp));
+
+				for (TradePresenceData tradePresenceData : tradePresences) {
+					if (tradePresenceData.getTimestamp() == timestamp)
+						bytes.write(tradePresenceData.getPublicKey());
+				}
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetTradePresencesMessage(int id, List<TradePresenceData> tradePresences) {
@@ -37,7 +74,7 @@ public class GetTradePresencesMessage extends Message {
 		return this.tradePresences;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int groupedEntriesCount = bytes.getInt();
 
 		List<TradePresenceData> tradePresences = new ArrayList<>(groupedEntriesCount);
@@ -63,48 +100,4 @@ public class GetTradePresencesMessage extends Message {
 		return new GetTradePresencesMessage(id, tradePresences);
 	}
 
-	@Override
-	protected synchronized byte[] toData() {
-		if (this.cachedData != null)
-			return this.cachedData;
-
-		// Shortcut in case we have no trade presences
-		if (this.tradePresences.isEmpty()) {
-			this.cachedData = Ints.toByteArray(0);
-			return this.cachedData;
-		}
-
-		// How many of each timestamp
-		Map<Long, Integer> countByTimestamp = new HashMap<>();
-
-		for (TradePresenceData tradePresenceData : this.tradePresences) {
-			Long timestamp = tradePresenceData.getTimestamp();
-			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
-		}
-
-		// We should know exactly how many bytes to allocate now
-		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
-				+ this.tradePresences.size() * Transformer.PUBLIC_KEY_LENGTH;
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
-
-			for (long timestamp : countByTimestamp.keySet()) {
-				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
-
-				bytes.write(Longs.toByteArray(timestamp));
-
-				for (TradePresenceData tradePresenceData : this.tradePresences) {
-					if (tradePresenceData.getTimestamp() == timestamp)
-						bytes.write(tradePresenceData.getPublicKey());
-				}
-			}
-
-			this.cachedData = bytes.toByteArray();
-			return this.cachedData;
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetTransactionMessage.java

@@ -1,20 +1,19 @@
 package org.qortal.network.message;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
+import java.util.Arrays;
 
 import org.qortal.transform.Transformer;
 
 public class GetTransactionMessage extends Message {
 
-	private static final int TRANSACTION_SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
 	private byte[] signature;
 
 	public GetTransactionMessage(byte[] signature) {
-		this(-1, signature);
+		super(MessageType.GET_TRANSACTION);
+
+		this.dataBytes = Arrays.copyOf(signature, signature.length);
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private GetTransactionMessage(int id, byte[] signature) {
@@ -27,28 +26,12 @@ public class GetTransactionMessage extends Message {
 		return this.signature;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
-		if (bytes.remaining() != TRANSACTION_SIGNATURE_LENGTH)
-			return null;
-
-		byte[] signature = new byte[TRANSACTION_SIGNATURE_LENGTH];
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 
 		bytes.get(signature);
 
 		return new GetTransactionMessage(id, signature);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(this.signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/GetUnconfirmedTransactionsMessage.java

@@ -1,25 +1,21 @@
 package org.qortal.network.message;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 public class GetUnconfirmedTransactionsMessage extends Message {
 
 	public GetUnconfirmedTransactionsMessage() {
-		this(-1);
+		super(MessageType.GET_UNCONFIRMED_TRANSACTIONS);
+
+		this.dataBytes = EMPTY_DATA_BYTES;
 	}
 
 	private GetUnconfirmedTransactionsMessage(int id) {
 		super(id, MessageType.GET_UNCONFIRMED_TRANSACTIONS);
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		return new GetUnconfirmedTransactionsMessage(id);
 	}
 
-	@Override
-	protected byte[] toData() {
-		return new byte[0];
-	}
-
 }

src/main/java/org/qortal/network/message/GoodbyeMessage.java

@@ -3,7 +3,6 @@ package org.qortal.network.message;
 import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.toMap;
 
-import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.Map;
 
@@ -22,7 +21,7 @@ public class GoodbyeMessage extends Message {
 		private static final Map<Integer, Reason> map = stream(Reason.values())
 				.collect(toMap(reason -> reason.value, reason -> reason));
 
-		private Reason(int value) {
+		Reason(int value) {
 			this.value = value;
 		}
 
@@ -31,7 +30,14 @@ public class GoodbyeMessage extends Message {
 		}
 	}
 
-	private final Reason reason;
+	private Reason reason;
+
+	public GoodbyeMessage(Reason reason) {
+		super(MessageType.GOODBYE);
+
+		this.dataBytes = Ints.toByteArray(reason.value);
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
 
 	private GoodbyeMessage(int id, Reason reason) {
 		super(id, MessageType.GOODBYE);
@@ -39,27 +45,18 @@ public class GoodbyeMessage extends Message {
 		this.reason = reason;
 	}
 
-	public GoodbyeMessage(Reason reason) {
-		this(-1, reason);
-	}
-
 	public Reason getReason() {
 		return this.reason;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) {
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
 		int reasonValue = byteBuffer.getInt();
 
 		Reason reason = Reason.valueOf(reasonValue);
 		if (reason == null)
-			return null;
+			throw new MessageException("Invalid reason " + reasonValue + " in GOODBYE message");
 
 		return new GoodbyeMessage(id, reason);
 	}
 
-	@Override
-	protected byte[] toData() throws IOException {
-		return Ints.toByteArray(this.reason.value);
-	}
-
 }

src/main/java/org/qortal/network/message/HeightV2Message.java

@@ -2,7 +2,6 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 import org.qortal.transform.Transformer;
@@ -19,7 +18,24 @@ public class HeightV2Message extends Message {
 	private byte[] minterPublicKey;
 
 	public HeightV2Message(int height, byte[] signature, long timestamp, byte[] minterPublicKey) {
-		this(-1, height, signature, timestamp, minterPublicKey);
+		super(MessageType.HEIGHT_V2);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(height));
+
+			bytes.write(signature);
+
+			bytes.write(Longs.toByteArray(timestamp));
+
+			bytes.write(minterPublicKey);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private HeightV2Message(int id, int height, byte[] signature, long timestamp, byte[] minterPublicKey) {
@@ -47,7 +63,7 @@ public class HeightV2Message extends Message {
 		return this.minterPublicKey;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int height = bytes.getInt();
 
 		byte[] signature = new byte[BlockTransformer.BLOCK_SIGNATURE_LENGTH];
@@ -61,23 +77,4 @@ public class HeightV2Message extends Message {
 		return new HeightV2Message(id, height, signature, timestamp, minterPublicKey);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.height));
-
-			bytes.write(this.signature);
-
-			bytes.write(Longs.toByteArray(this.timestamp));
-
-			bytes.write(this.minterPublicKey);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/HelloMessage.java

@@ -11,9 +11,28 @@ import com.google.common.primitives.Longs;
 
 public class HelloMessage extends Message {
 
-	private final long timestamp;
-	private final String versionString;
-	private final String senderPeerAddress;
+	private long timestamp;
+	private String versionString;
+	private String senderPeerAddress;
+
+	public HelloMessage(long timestamp, String versionString, String senderPeerAddress) {
+		super(MessageType.HELLO);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Longs.toByteArray(timestamp));
+
+			Serialization.serializeSizedString(bytes, versionString);
+
+			Serialization.serializeSizedString(bytes, senderPeerAddress);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
 
 	private HelloMessage(int id, long timestamp, String versionString, String senderPeerAddress) {
 		super(id, MessageType.HELLO);
@@ -23,10 +42,6 @@ public class HelloMessage extends Message {
 		this.senderPeerAddress = senderPeerAddress;
 	}
 
-	public HelloMessage(long timestamp, String versionString, String senderPeerAddress) {
-		this(-1, timestamp, versionString, senderPeerAddress);
-	}
-
 	public long getTimestamp() {
 		return this.timestamp;
 	}
@@ -39,31 +54,23 @@ public class HelloMessage extends Message {
 		return this.senderPeerAddress;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws TransformationException {
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
 		long timestamp = byteBuffer.getLong();
 
-		String versionString = Serialization.deserializeSizedString(byteBuffer, 255);
-
-		// Sender peer address added in v3.0, so is an optional field. Older versions won't send it.
+		String versionString;
 		String senderPeerAddress = null;
-		if (byteBuffer.hasRemaining()) {
-			senderPeerAddress = Serialization.deserializeSizedString(byteBuffer, 255);
+		try {
+			versionString = Serialization.deserializeSizedString(byteBuffer, 255);
+
+			// Sender peer address added in v3.0, so is an optional field. Older versions won't send it.
+			if (byteBuffer.hasRemaining()) {
+				senderPeerAddress = Serialization.deserializeSizedString(byteBuffer, 255);
+			}
+		} catch (TransformationException e) {
+			throw new MessageException(e.getMessage(), e);
 		}
 
 		return new HelloMessage(id, timestamp, versionString, senderPeerAddress);
 	}
 
-	@Override
-	protected byte[] toData() throws IOException {
-		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-		bytes.write(Longs.toByteArray(this.timestamp));
-
-		Serialization.serializeSizedString(bytes, this.versionString);
-
-		Serialization.serializeSizedString(bytes, this.senderPeerAddress);
-
-		return bytes.toByteArray();
-	}
-
 }

src/main/java/org/qortal/network/message/Message.java

@@ -1,161 +1,67 @@
 package org.qortal.network.message;
 
-import java.util.Map;
-
 import org.qortal.crypto.Crypto;
 import org.qortal.network.Network;
-import org.qortal.transform.TransformationException;
 
 import com.google.common.primitives.Ints;
 
-import static java.util.Arrays.stream;
-import static java.util.stream.Collectors.toMap;
-
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 
+/**
+ * Network message for sending over network, or unpacked data received from network.
+ * <p></p>
+ * <p>
+ * For messages received from network, subclass's {@code fromByteBuffer()} method is used
+ * to construct a subclassed instance. Original bytes from network are not retained.
+ * Access to deserialized data should be via subclass's getters. Ideally there should be NO setters!
+ * </p>
+ * <p></p>
+ * <p>
+ * Each subclass's <b>public</b> constructor is for building a message to send <b>only</b>.
+ * The constructor will serialize into byte form but <b>not</b> store the passed args.
+ * Serialized bytes are saved into superclass (Message) {@code dataBytes} and, if not empty,
+ * a checksum is created and saved into {@code checksumBytes}.
+ * Therefore: <i>do not use subclass's getters after using constructor!</i>
+ * </p>
+ * <p></p>
+ * <p>
+ * For subclasses where outgoing versions might be usefully cached, they can implement Clonable
+ * as long if they are safe to use {@link Object#clone()}.
+ * </p>
+ */
 public abstract class Message {
 
 	// MAGIC(4) + TYPE(4) + HAS-ID(1) + ID?(4) + DATA-SIZE(4) + CHECKSUM?(4) + DATA?(*)
 	private static final int MAGIC_LENGTH = 4;
+	private static final int TYPE_LENGTH = 4;
+	private static final int HAS_ID_LENGTH = 1;
+	private static final int ID_LENGTH = 4;
+	private static final int DATA_SIZE_LENGTH = 4;
 	private static final int CHECKSUM_LENGTH = 4;
 
 	private static final int MAX_DATA_SIZE = 10 * 1024 * 1024; // 10MB
 
-	@SuppressWarnings("serial")
-	public static class MessageException extends Exception {
-		public MessageException() {
-		}
+	protected static final byte[] EMPTY_DATA_BYTES = new byte[0];
 
-		public MessageException(String message) {
-			super(message);
-		}
+	protected int id;
+	protected final MessageType type;
 
-		public MessageException(String message, Throwable cause) {
-			super(message, cause);
-		}
-
-		public MessageException(Throwable cause) {
-			super(cause);
-		}
-	}
-
-	public enum MessageType {
-		// Handshaking
-		HELLO(0),
-		GOODBYE(1),
-		CHALLENGE(2),
-		RESPONSE(3),
-
-		// Status / notifications
-		HEIGHT_V2(10),
-		PING(11),
-		PONG(12),
-
-		// Requesting data
-		PEERS_V2(20),
-		GET_PEERS(21),
-
-		TRANSACTION(30),
-		GET_TRANSACTION(31),
-
-		TRANSACTION_SIGNATURES(40),
-		GET_UNCONFIRMED_TRANSACTIONS(41),
-
-		BLOCK(50),
-		GET_BLOCK(51),
-
-		SIGNATURES(60),
-		GET_SIGNATURES_V2(61),
-
-		BLOCK_SUMMARIES(70),
-		GET_BLOCK_SUMMARIES(71),
-
-		ONLINE_ACCOUNTS(80),
-		GET_ONLINE_ACCOUNTS(81),
-		ONLINE_ACCOUNTS_V2(82),
-		GET_ONLINE_ACCOUNTS_V2(83),
-
-		ARBITRARY_DATA(90),
-		GET_ARBITRARY_DATA(91),
-
-		BLOCKS(100),
-		GET_BLOCKS(101),
-
-		ARBITRARY_DATA_FILE(110),
-		GET_ARBITRARY_DATA_FILE(111),
-
-		ARBITRARY_DATA_FILE_LIST(120),
-		GET_ARBITRARY_DATA_FILE_LIST(121),
-
-		ARBITRARY_SIGNATURES(130),
-
-		TRADE_PRESENCES(140),
-		GET_TRADE_PRESENCES(141),
-		
-		ARBITRARY_METADATA(150),
-		GET_ARBITRARY_METADATA(151);
-
-		public final int value;
-		public final Method fromByteBufferMethod;
-
-		private static final Map<Integer, MessageType> map = stream(MessageType.values())
-				.collect(toMap(messageType -> messageType.value, messageType -> messageType));
-
-		private MessageType(int value) {
-			this.value = value;
-
-			String[] classNameParts = this.name().toLowerCase().split("_");
-
-			for (int i = 0; i < classNameParts.length; ++i)
-				classNameParts[i] = classNameParts[i].substring(0, 1).toUpperCase().concat(classNameParts[i].substring(1));
-
-			String className = String.join("", classNameParts);
-
-			Method method;
-			try {
-				Class<?> subclass = Class.forName(String.join("", Message.class.getPackage().getName(), ".", className, "Message"));
-
-				method = subclass.getDeclaredMethod("fromByteBuffer", int.class, ByteBuffer.class);
-			} catch (ClassNotFoundException | NoSuchMethodException | SecurityException e) {
-				method = null;
-			}
-
-			this.fromByteBufferMethod = method;
-		}
-
-		public static MessageType valueOf(int value) {
-			return map.get(value);
-		}
-
-		public Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
-			if (this.fromByteBufferMethod == null)
-				throw new MessageException("Unsupported message type [" + value + "] during conversion from bytes");
-
-			try {
-				return (Message) this.fromByteBufferMethod.invoke(null, id, byteBuffer);
-			} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
-				if (e.getCause() instanceof BufferUnderflowException)
-					throw new MessageException("Byte data too short for " + name() + " message");
-
-				throw new MessageException("Internal error with " + name() + " message during conversion from bytes");
-			}
-		}
-	}
-
-	private int id;
-	private MessageType type;
+	/** Serialized outgoing message data. Expected to be written to by subclass. */
+	protected byte[] dataBytes;
+	/** Serialized outgoing message checksum. Expected to be written to by subclass. */
+	protected byte[] checksumBytes;
 
+	/** Typically called by subclass when constructing message from received network data. */
 	protected Message(int id, MessageType type) {
 		this.id = id;
 		this.type = type;
 	}
 
+	/** Typically called by subclass when constructing outgoing message. */
 	protected Message(MessageType type) {
 		this(-1, type);
 	}
@@ -179,9 +85,9 @@ public abstract class Message {
 	/**
 	 * Attempt to read a message from byte buffer.
 	 * 
-	 * @param readOnlyBuffer
+	 * @param readOnlyBuffer ByteBuffer containing bytes read from network
 	 * @return null if no complete message can be read
-	 * @throws MessageException
+	 * @throws MessageException if message could not be decoded or is invalid
 	 */
 	public static Message fromByteBuffer(ByteBuffer readOnlyBuffer) throws MessageException {
 		try {
@@ -256,9 +162,27 @@ public abstract class Message {
 		return Arrays.copyOfRange(Crypto.digest(dataBuffer), 0, CHECKSUM_LENGTH);
 	}
 
+	public void checkValidOutgoing() throws MessageException {
+		// We expect subclass to have initialized these
+		if (this.dataBytes == null)
+			throw new MessageException("Missing data payload");
+		if (this.dataBytes.length > 0 && this.checksumBytes == null)
+			throw new MessageException("Missing data checksum");
+	}
+
 	public byte[] toBytes() throws MessageException {
+		checkValidOutgoing();
+
+		// We can calculate exact length
+		int messageLength = MAGIC_LENGTH + TYPE_LENGTH + HAS_ID_LENGTH;
+		messageLength += this.hasId() ? ID_LENGTH : 0;
+		messageLength += DATA_SIZE_LENGTH + this.dataBytes.length > 0 ? CHECKSUM_LENGTH + this.dataBytes.length : 0;
+
+		if (messageLength > MAX_DATA_SIZE)
+			throw new MessageException(String.format("About to send message with length %d larger than allowed %d", messageLength, MAX_DATA_SIZE));
+
 		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream(256);
+			ByteArrayOutputStream bytes = new ByteArrayOutputStream(messageLength);
 
 			// Magic
 			bytes.write(Network.getInstance().getMessageMagic());
@@ -273,26 +197,30 @@ public abstract class Message {
 				bytes.write(0);
 			}
 
-			byte[] data = this.toData();
-			if (data == null)
-				throw new MessageException("Missing data payload");
+			bytes.write(Ints.toByteArray(this.dataBytes.length));
 
-			bytes.write(Ints.toByteArray(data.length));
-
-			if (data.length > 0) {
-				bytes.write(generateChecksum(data));
-				bytes.write(data);
+			if (this.dataBytes.length > 0) {
+				bytes.write(this.checksumBytes);
+				bytes.write(this.dataBytes);
 			}
 
-			if (bytes.size() > MAX_DATA_SIZE)
-				throw new MessageException(String.format("About to send message with length %d larger than allowed %d", bytes.size(), MAX_DATA_SIZE));
-
 			return bytes.toByteArray();
-		} catch (IOException | TransformationException e) {
+		} catch (IOException e) {
 			throw new MessageException("Failed to serialize message", e);
 		}
 	}
 
-	protected abstract byte[] toData() throws IOException, TransformationException;
+	public static <M extends Message> M cloneWithNewId(M message, int newId) {
+		M clone;
+
+		try {
+			clone = (M) message.clone();
+		} catch (CloneNotSupportedException e) {
+			throw new UnsupportedOperationException("Message sub-class not cloneable");
+		}
+
+		clone.setId(newId);
+		return clone;
+	}
 
 }

src/main/java/org/qortal/network/message/MessageException.java

@@ -0,0 +1,19 @@
+package org.qortal.network.message;
+
+@SuppressWarnings("serial")
+public class MessageException extends Exception {
+    public MessageException() {
+    }
+
+    public MessageException(String message) {
+        super(message);
+    }
+
+    public MessageException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public MessageException(Throwable cause) {
+        super(cause);
+    }
+}

src/main/java/org/qortal/network/message/MessageProducer.java

@@ -0,0 +1,8 @@
+package org.qortal.network.message;
+
+import java.nio.ByteBuffer;
+
+@FunctionalInterface
+public interface MessageProducer {
+    Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException;
+}

src/main/java/org/qortal/network/message/MessageType.java

@@ -0,0 +1,96 @@
+package org.qortal.network.message;
+
+import java.nio.BufferUnderflowException;
+import java.nio.ByteBuffer;
+import java.util.Map;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+public enum MessageType {
+    // Handshaking
+    HELLO(0, HelloMessage::fromByteBuffer),
+    GOODBYE(1, GoodbyeMessage::fromByteBuffer),
+    CHALLENGE(2, ChallengeMessage::fromByteBuffer),
+    RESPONSE(3, ResponseMessage::fromByteBuffer),
+
+    // Status / notifications
+    HEIGHT_V2(10, HeightV2Message::fromByteBuffer),
+    PING(11, PingMessage::fromByteBuffer),
+    PONG(12, PongMessage::fromByteBuffer),
+
+    // Requesting data
+    PEERS_V2(20, PeersV2Message::fromByteBuffer),
+    GET_PEERS(21, GetPeersMessage::fromByteBuffer),
+
+    TRANSACTION(30, TransactionMessage::fromByteBuffer),
+    GET_TRANSACTION(31, GetTransactionMessage::fromByteBuffer),
+
+    TRANSACTION_SIGNATURES(40, TransactionSignaturesMessage::fromByteBuffer),
+    GET_UNCONFIRMED_TRANSACTIONS(41, GetUnconfirmedTransactionsMessage::fromByteBuffer),
+
+    BLOCK(50, BlockMessage::fromByteBuffer),
+    GET_BLOCK(51, GetBlockMessage::fromByteBuffer),
+
+    SIGNATURES(60, SignaturesMessage::fromByteBuffer),
+    GET_SIGNATURES_V2(61, GetSignaturesV2Message::fromByteBuffer),
+
+    BLOCK_SUMMARIES(70, BlockSummariesMessage::fromByteBuffer),
+    GET_BLOCK_SUMMARIES(71, GetBlockSummariesMessage::fromByteBuffer),
+
+    ONLINE_ACCOUNTS(80, OnlineAccountsMessage::fromByteBuffer),
+    GET_ONLINE_ACCOUNTS(81, GetOnlineAccountsMessage::fromByteBuffer),
+    ONLINE_ACCOUNTS_V2(82, OnlineAccountsV2Message::fromByteBuffer),
+    GET_ONLINE_ACCOUNTS_V2(83, GetOnlineAccountsV2Message::fromByteBuffer),
+
+    ARBITRARY_DATA(90, ArbitraryDataMessage::fromByteBuffer),
+    GET_ARBITRARY_DATA(91, GetArbitraryDataMessage::fromByteBuffer),
+
+    BLOCKS(100, null), // unsupported
+    GET_BLOCKS(101, null), // unsupported
+
+    ARBITRARY_DATA_FILE(110, ArbitraryDataFileMessage::fromByteBuffer),
+    GET_ARBITRARY_DATA_FILE(111, GetArbitraryDataFileMessage::fromByteBuffer),
+
+    ARBITRARY_DATA_FILE_LIST(120, ArbitraryDataFileListMessage::fromByteBuffer),
+    GET_ARBITRARY_DATA_FILE_LIST(121, GetArbitraryDataFileListMessage::fromByteBuffer),
+
+    ARBITRARY_SIGNATURES(130, ArbitrarySignaturesMessage::fromByteBuffer),
+
+    TRADE_PRESENCES(140, TradePresencesMessage::fromByteBuffer),
+    GET_TRADE_PRESENCES(141, GetTradePresencesMessage::fromByteBuffer),
+
+    ARBITRARY_METADATA(150, ArbitraryMetadataMessage::fromByteBuffer),
+    GET_ARBITRARY_METADATA(151, GetArbitraryMetadataMessage::fromByteBuffer);
+
+    public final int value;
+    public final MessageProducer fromByteBufferMethod;
+
+    private static final Map<Integer, MessageType> map = stream(MessageType.values())
+            .collect(toMap(messageType -> messageType.value, messageType -> messageType));
+
+    MessageType(int value, MessageProducer fromByteBufferMethod) {
+        this.value = value;
+        this.fromByteBufferMethod = fromByteBufferMethod;
+    }
+
+    public static MessageType valueOf(int value) {
+        return map.get(value);
+    }
+
+    /**
+     * Attempt to read a message from byte buffer.
+     *
+     * @param id message ID or -1
+     * @param byteBuffer ByteBuffer source for message
+     * @return null if no complete message can be read
+     * @throws MessageException if message could not be decoded or is invalid
+     * @throws BufferUnderflowException if not enough bytes in buffer to read message
+     */
+    public Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+        if (this.fromByteBufferMethod == null)
+            throw new MessageException("Message type " + this.name() + " unsupported");
+
+        return this.fromByteBufferMethod.fromByteBuffer(id, byteBuffer);
+    }
+}

src/main/java/org/qortal/network/message/OnlineAccountsMessage.java

@@ -2,7 +2,6 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -20,7 +19,26 @@ public class OnlineAccountsMessage extends Message {
 	private List<OnlineAccountData> onlineAccounts;
 
 	public OnlineAccountsMessage(List<OnlineAccountData> onlineAccounts) {
-		this(-1, onlineAccounts);
+		super(MessageType.ONLINE_ACCOUNTS);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(onlineAccounts.size()));
+
+			for (OnlineAccountData onlineAccountData : onlineAccounts) {
+				bytes.write(Longs.toByteArray(onlineAccountData.getTimestamp()));
+
+				bytes.write(onlineAccountData.getSignature());
+
+				bytes.write(onlineAccountData.getPublicKey());
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private OnlineAccountsMessage(int id, List<OnlineAccountData> onlineAccounts) {
@@ -33,7 +51,7 @@ public class OnlineAccountsMessage extends Message {
 		return this.onlineAccounts;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		final int accountCount = bytes.getInt();
 
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
@@ -54,27 +72,4 @@ public class OnlineAccountsMessage extends Message {
 		return new OnlineAccountsMessage(id, onlineAccounts);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.onlineAccounts.size()));
-
-			for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-				OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-
-				bytes.write(Longs.toByteArray(onlineAccountData.getTimestamp()));
-
-				bytes.write(onlineAccountData.getSignature());
-
-				bytes.write(onlineAccountData.getPublicKey());
-			}
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/OnlineAccountsV2Message.java

@@ -7,13 +7,11 @@ import org.qortal.transform.Transformer;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 /**
  * For sending online accounts info to remote peer.
@@ -25,11 +23,52 @@ import java.util.stream.Collectors;
  * Also V2 only builds online accounts message once!
  */
 public class OnlineAccountsV2Message extends Message {
+
 	private List<OnlineAccountData> onlineAccounts;
-	private byte[] cachedData;
 
 	public OnlineAccountsV2Message(List<OnlineAccountData> onlineAccounts) {
-		this(-1, onlineAccounts);
+		super(MessageType.ONLINE_ACCOUNTS_V2);
+
+		// Shortcut in case we have no online accounts
+		if (onlineAccounts.isEmpty()) {
+			this.dataBytes = Ints.toByteArray(0);
+			this.checksumBytes = Message.generateChecksum(this.dataBytes);
+			return;
+		}
+
+		// How many of each timestamp
+		Map<Long, Integer> countByTimestamp = new HashMap<>();
+
+		for (OnlineAccountData onlineAccountData : onlineAccounts) {
+			Long timestamp = onlineAccountData.getTimestamp();
+			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
+		}
+
+		// We should know exactly how many bytes to allocate now
+		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
+				+ onlineAccounts.size() * (Transformer.SIGNATURE_LENGTH + Transformer.PUBLIC_KEY_LENGTH);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
+
+		try {
+			for (long timestamp : countByTimestamp.keySet()) {
+				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
+
+				bytes.write(Longs.toByteArray(timestamp));
+
+				for (OnlineAccountData onlineAccountData : onlineAccounts) {
+					if (onlineAccountData.getTimestamp() == timestamp) {
+						bytes.write(onlineAccountData.getSignature());
+						bytes.write(onlineAccountData.getPublicKey());
+					}
+				}
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private OnlineAccountsV2Message(int id, List<OnlineAccountData> onlineAccounts) {
@@ -42,7 +81,7 @@ public class OnlineAccountsV2Message extends Message {
 		return this.onlineAccounts;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws MessageException {
 		int accountCount = bytes.getInt();
 
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
@@ -71,54 +110,4 @@ public class OnlineAccountsV2Message extends Message {
 		return new OnlineAccountsV2Message(id, onlineAccounts);
 	}
 
-	@Override
-	protected synchronized byte[] toData() {
-		if (this.cachedData != null)
-			return this.cachedData;
-
-		// Shortcut in case we have no online accounts
-		if (this.onlineAccounts.isEmpty()) {
-			this.cachedData = Ints.toByteArray(0);
-			return this.cachedData;
-		}
-
-		// How many of each timestamp
-		Map<Long, Integer> countByTimestamp = new HashMap<>();
-
-		for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-			OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-			Long timestamp = onlineAccountData.getTimestamp();
-			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
-		}
-
-		// We should know exactly how many bytes to allocate now
-		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
-				+ this.onlineAccounts.size() * (Transformer.SIGNATURE_LENGTH + Transformer.PUBLIC_KEY_LENGTH);
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
-
-			for (long timestamp : countByTimestamp.keySet()) {
-				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
-
-				bytes.write(Longs.toByteArray(timestamp));
-
-				for (int i = 0; i < this.onlineAccounts.size(); ++i) {
-					OnlineAccountData onlineAccountData = this.onlineAccounts.get(i);
-
-					if (onlineAccountData.getTimestamp() == timestamp) {
-						bytes.write(onlineAccountData.getSignature());
-
-						bytes.write(onlineAccountData.getPublicKey());
-					}
-				}
-			}
-
-			this.cachedData = bytes.toByteArray();
-			return this.cachedData;
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/PeersV2Message.java

@@ -2,7 +2,6 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
@@ -19,7 +18,35 @@ public class PeersV2Message extends Message {
 	private List<PeerAddress> peerAddresses;
 
 	public PeersV2Message(List<PeerAddress> peerAddresses) {
-		this(-1, peerAddresses);
+		super(MessageType.PEERS_V2);
+
+		List<byte[]> addresses = new ArrayList<>();
+
+		// First entry represents sending node but contains only port number with empty address.
+		addresses.add(("0.0.0.0:" + Settings.getInstance().getListenPort()).getBytes(StandardCharsets.UTF_8));
+
+		for (PeerAddress peerAddress : peerAddresses)
+			addresses.add(peerAddress.toString().getBytes(StandardCharsets.UTF_8));
+
+		// We can't send addresses that are longer than 255 bytes as length itself is encoded in one byte.
+		addresses.removeIf(addressString -> addressString.length > 255);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			// Number of entries
+			bytes.write(Ints.toByteArray(addresses.size()));
+
+			for (byte[] address : addresses) {
+				bytes.write(address.length);
+				bytes.write(address);
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private PeersV2Message(int id, List<PeerAddress> peerAddresses) {
@@ -32,7 +59,7 @@ public class PeersV2Message extends Message {
 		return this.peerAddresses;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
 		// Read entry count
 		int count = byteBuffer.getInt();
 
@@ -49,43 +76,11 @@ public class PeersV2Message extends Message {
 				PeerAddress peerAddress = PeerAddress.fromString(addressString);
 				peerAddresses.add(peerAddress);
 			} catch (IllegalArgumentException e) {
-				// Not valid - ignore
+				throw new MessageException("Invalid peer address in received PEERS_V2 message");
 			}
 		}
 
 		return new PeersV2Message(id, peerAddresses);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			List<byte[]> addresses = new ArrayList<>();
-
-			// First entry represents sending node but contains only port number with empty address.
-			addresses.add(("0.0.0.0:" + Settings.getInstance().getListenPort()).getBytes(StandardCharsets.UTF_8));
-
-			for (PeerAddress peerAddress : this.peerAddresses)
-				addresses.add(peerAddress.toString().getBytes(StandardCharsets.UTF_8));
-
-			// We can't send addresses that are longer than 255 bytes as length itself is encoded in one byte.
-			addresses.removeIf(addressString -> addressString.length > 255);
-
-			// Serialize
-
-			// Number of entries
-			bytes.write(Ints.toByteArray(addresses.size()));
-
-			for (byte[] address : addresses) {
-				bytes.write(address.length);
-				bytes.write(address);
-			}
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/PingMessage.java

@@ -1,25 +1,21 @@
 package org.qortal.network.message;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 public class PingMessage extends Message {
 
 	public PingMessage() {
-		this(-1);
+		super(MessageType.PING);
+
+		this.dataBytes = EMPTY_DATA_BYTES;
 	}
 
 	private PingMessage(int id) {
 		super(id, MessageType.PING);
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		return new PingMessage(id);
 	}
 
-	@Override
-	protected byte[] toData() {
-		return new byte[0];
-	}
-
 }

src/main/java/org/qortal/network/message/PongMessage.java

@@ -0,0 +1,21 @@
+package org.qortal.network.message;
+
+import java.nio.ByteBuffer;
+
+public class PongMessage extends Message {
+
+	public PongMessage() {
+		super(MessageType.PONG);
+
+		this.dataBytes = EMPTY_DATA_BYTES;
+	}
+
+	private PongMessage(int id) {
+		super(id, MessageType.PONG);
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
+		return new PongMessage(id);
+	}
+
+}

src/main/java/org/qortal/network/message/ResponseMessage.java

@@ -10,8 +10,25 @@ public class ResponseMessage extends Message {
 
 	public static final int DATA_LENGTH = 32;
 
-	private final int nonce;
-	private final byte[] data;
+	private int nonce;
+	private byte[] data;
+
+	public ResponseMessage(int nonce, byte[] data) {
+		super(MessageType.RESPONSE);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(4 + DATA_LENGTH);
+
+		try {
+			bytes.write(Ints.toByteArray(nonce));
+
+			bytes.write(data);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
 
 	private ResponseMessage(int id, int nonce, byte[] data) {
 		super(id, MessageType.RESPONSE);
@@ -20,10 +37,6 @@ public class ResponseMessage extends Message {
 		this.data = data;
 	}
 
-	public ResponseMessage(int nonce, byte[] data) {
-		this(-1, nonce, data);
-	}
-
 	public int getNonce() {
 		return this.nonce;
 	}
@@ -41,15 +54,4 @@ public class ResponseMessage extends Message {
 		return new ResponseMessage(id, nonce, data);
 	}
 
-	@Override
-	protected byte[] toData() throws IOException {
-		ByteArrayOutputStream bytes = new ByteArrayOutputStream(4 + DATA_LENGTH);
-
-		bytes.write(Ints.toByteArray(this.nonce));
-
-		bytes.write(data);
-
-		return bytes.toByteArray();
-	}
-
 }

src/main/java/org/qortal/network/message/SignaturesMessage.java

@@ -2,7 +2,7 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -13,12 +13,24 @@ import com.google.common.primitives.Ints;
 
 public class SignaturesMessage extends Message {
 
-	private static final int BLOCK_SIGNATURE_LENGTH = BlockTransformer.BLOCK_SIGNATURE_LENGTH;
-
 	private List<byte[]> signatures;
 
 	public SignaturesMessage(List<byte[]> signatures) {
-		this(-1, signatures);
+		super(MessageType.SIGNATURES);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(signatures.size()));
+
+			for (byte[] signature : signatures)
+				bytes.write(signature);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private SignaturesMessage(int id, List<byte[]> signatures) {
@@ -31,15 +43,15 @@ public class SignaturesMessage extends Message {
 		return this.signatures;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int count = bytes.getInt();
 
-		if (bytes.remaining() != count * BLOCK_SIGNATURE_LENGTH)
-			return null;
+		if (bytes.remaining() < count * BlockTransformer.BLOCK_SIGNATURE_LENGTH)
+			throw new BufferUnderflowException();
 
 		List<byte[]> signatures = new ArrayList<>();
 		for (int i = 0; i < count; ++i) {
-			byte[] signature = new byte[BLOCK_SIGNATURE_LENGTH];
+			byte[] signature = new byte[BlockTransformer.BLOCK_SIGNATURE_LENGTH];
 			bytes.get(signature);
 			signatures.add(signature);
 		}
@@ -47,20 +59,4 @@ public class SignaturesMessage extends Message {
 		return new SignaturesMessage(id, signatures);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.signatures.size()));
-
-			for (byte[] signature : this.signatures)
-				bytes.write(signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/TradePresencesMessage.java

@@ -8,7 +8,6 @@ import org.qortal.utils.Base58;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -21,11 +20,55 @@ import java.util.Map;
  * Groups of: number of entries, timestamp, then pubkey + sig + AT address for each entry.
  */
 public class TradePresencesMessage extends Message {
+
 	private List<TradePresenceData> tradePresences;
-	private byte[] cachedData;
 
 	public TradePresencesMessage(List<TradePresenceData> tradePresences) {
-		this(-1, tradePresences);
+		super(MessageType.TRADE_PRESENCES);
+
+		// Shortcut in case we have no trade presences
+		if (tradePresences.isEmpty()) {
+			this.dataBytes = Ints.toByteArray(0);
+			this.checksumBytes = Message.generateChecksum(this.dataBytes);
+			return;
+		}
+
+		// How many of each timestamp
+		Map<Long, Integer> countByTimestamp = new HashMap<>();
+
+		for (TradePresenceData tradePresenceData : tradePresences) {
+			Long timestamp = tradePresenceData.getTimestamp();
+			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
+		}
+
+		// We should know exactly how many bytes to allocate now
+		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
+				+ tradePresences.size() * (Transformer.PUBLIC_KEY_LENGTH + Transformer.SIGNATURE_LENGTH + Transformer.ADDRESS_LENGTH);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
+
+		try {
+			for (long timestamp : countByTimestamp.keySet()) {
+				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
+
+				bytes.write(Longs.toByteArray(timestamp));
+
+				for (TradePresenceData tradePresenceData : tradePresences) {
+					if (tradePresenceData.getTimestamp() == timestamp) {
+						bytes.write(tradePresenceData.getPublicKey());
+
+						bytes.write(tradePresenceData.getSignature());
+
+						bytes.write(Base58.decode(tradePresenceData.getAtAddress()));
+					}
+				}
+			}
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private TradePresencesMessage(int id, List<TradePresenceData> tradePresences) {
@@ -38,7 +81,7 @@ public class TradePresencesMessage extends Message {
 		return this.tradePresences;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int groupedEntriesCount = bytes.getInt();
 
 		List<TradePresenceData> tradePresences = new ArrayList<>(groupedEntriesCount);
@@ -71,53 +114,4 @@ public class TradePresencesMessage extends Message {
 		return new TradePresencesMessage(id, tradePresences);
 	}
 
-	@Override
-	protected synchronized byte[] toData() {
-		if (this.cachedData != null)
-			return this.cachedData;
-
-		// Shortcut in case we have no trade presences
-		if (this.tradePresences.isEmpty()) {
-			this.cachedData = Ints.toByteArray(0);
-			return this.cachedData;
-		}
-
-		// How many of each timestamp
-		Map<Long, Integer> countByTimestamp = new HashMap<>();
-
-		for (TradePresenceData tradePresenceData : this.tradePresences) {
-			Long timestamp = tradePresenceData.getTimestamp();
-			countByTimestamp.compute(timestamp, (k, v) -> v == null ? 1 : ++v);
-		}
-
-		// We should know exactly how many bytes to allocate now
-		int byteSize = countByTimestamp.size() * (Transformer.INT_LENGTH + Transformer.TIMESTAMP_LENGTH)
-				+ this.tradePresences.size() * (Transformer.PUBLIC_KEY_LENGTH + Transformer.SIGNATURE_LENGTH + Transformer.ADDRESS_LENGTH);
-
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream(byteSize);
-
-			for (long timestamp : countByTimestamp.keySet()) {
-				bytes.write(Ints.toByteArray(countByTimestamp.get(timestamp)));
-
-				bytes.write(Longs.toByteArray(timestamp));
-
-				for (TradePresenceData tradePresenceData : this.tradePresences) {
-					if (tradePresenceData.getTimestamp() == timestamp) {
-						bytes.write(tradePresenceData.getPublicKey());
-
-						bytes.write(tradePresenceData.getSignature());
-
-						bytes.write(Base58.decode(tradePresenceData.getAtAddress()));
-					}
-				}
-			}
-
-			this.cachedData = bytes.toByteArray();
-			return this.cachedData;
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/message/TransactionMessage.java

@@ -1,6 +1,5 @@
 package org.qortal.network.message;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 
 import org.qortal.data.transaction.TransactionData;
@@ -11,8 +10,11 @@ public class TransactionMessage extends Message {
 
 	private TransactionData transactionData;
 
-	public TransactionMessage(TransactionData transactionData) {
-		this(-1, transactionData);
+	public TransactionMessage(TransactionData transactionData) throws TransformationException {
+		super(MessageType.TRANSACTION);
+
+		this.dataBytes = TransactionTransformer.toBytes(transactionData);
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private TransactionMessage(int id, TransactionData transactionData) {
@@ -25,26 +27,16 @@ public class TransactionMessage extends Message {
 		return this.transactionData;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws UnsupportedEncodingException {
-		try {
-			TransactionData transactionData = TransactionTransformer.fromByteBuffer(byteBuffer);
-
-			return new TransactionMessage(id, transactionData);
-		} catch (TransformationException e) {
-			return null;
-		}
-	}
-
-	@Override
-	protected byte[] toData() {
-		if (this.transactionData == null)
-			return null;
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+		TransactionData transactionData;
 
 		try {
-			return TransactionTransformer.toBytes(this.transactionData);
+			transactionData = TransactionTransformer.fromByteBuffer(byteBuffer);
 		} catch (TransformationException e) {
-			return null;
+			throw new MessageException(e.getMessage(), e);
 		}
+
+		return new TransactionMessage(id, transactionData);
 	}
 
 }

src/main/java/org/qortal/network/message/TransactionSignaturesMessage.java

@@ -2,7 +2,7 @@ package org.qortal.network.message;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -13,12 +13,24 @@ import com.google.common.primitives.Ints;
 
 public class TransactionSignaturesMessage extends Message {
 
-	private static final int SIGNATURE_LENGTH = Transformer.SIGNATURE_LENGTH;
-
 	private List<byte[]> signatures;
 
 	public TransactionSignaturesMessage(List<byte[]> signatures) {
-		this(-1, signatures);
+		super(MessageType.TRANSACTION_SIGNATURES);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(signatures.size()));
+
+			for (byte[] signature : signatures)
+				bytes.write(signature);
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
 	}
 
 	private TransactionSignaturesMessage(int id, List<byte[]> signatures) {
@@ -31,15 +43,15 @@ public class TransactionSignaturesMessage extends Message {
 		return this.signatures;
 	}
 
-	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
+	public static Message fromByteBuffer(int id, ByteBuffer bytes) {
 		int count = bytes.getInt();
 
-		if (bytes.remaining() != count * SIGNATURE_LENGTH)
-			return null;
+		if (bytes.remaining() < count * Transformer.SIGNATURE_LENGTH)
+			throw new BufferUnderflowException();
 
 		List<byte[]> signatures = new ArrayList<>();
 		for (int i = 0; i < count; ++i) {
-			byte[] signature = new byte[SIGNATURE_LENGTH];
+			byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];
 			bytes.get(signature);
 			signatures.add(signature);
 		}
@@ -47,20 +59,4 @@ public class TransactionSignaturesMessage extends Message {
 		return new TransactionSignaturesMessage(id, signatures);
 	}
 
-	@Override
-	protected byte[] toData() {
-		try {
-			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-
-			bytes.write(Ints.toByteArray(this.signatures.size()));
-
-			for (byte[] signature : this.signatures)
-				bytes.write(signature);
-
-			return bytes.toByteArray();
-		} catch (IOException e) {
-			return null;
-		}
-	}
-
 }

src/main/java/org/qortal/network/task/BroadcastTask.java

@@ -0,0 +1,22 @@
+package org.qortal.network.task;
+
+import org.qortal.controller.Controller;
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.network.message.Message;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+public class BroadcastTask implements Task {
+    public BroadcastTask() {
+    }
+
+    @Override
+    public String getName() {
+        return "BroadcastTask";
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Controller.getInstance().doNetworkBroadcast();
+    }
+}

src/main/java/org/qortal/network/task/ChannelAcceptTask.java

@@ -0,0 +1,97 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.network.PeerAddress;
+import org.qortal.settings.Settings;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+import org.qortal.utils.NTP;
+
+import java.io.IOException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+import java.util.List;
+
+public class ChannelAcceptTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(ChannelAcceptTask.class);
+
+    private final ServerSocketChannel serverSocketChannel;
+
+    public ChannelAcceptTask(ServerSocketChannel serverSocketChannel) {
+        this.serverSocketChannel = serverSocketChannel;
+    }
+
+    @Override
+    public String getName() {
+        return "ChannelAcceptTask";
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Network network = Network.getInstance();
+        SocketChannel socketChannel;
+
+        try {
+            if (network.getImmutableConnectedPeers().size() >= network.getMaxPeers()) {
+                // We have enough peers
+                LOGGER.debug("Ignoring pending incoming connections because the server is full");
+                return;
+            }
+
+            socketChannel = serverSocketChannel.accept();
+
+            network.setInterestOps(serverSocketChannel, SelectionKey.OP_ACCEPT);
+        } catch (IOException e) {
+            return;
+        }
+
+        // No connection actually accepted?
+        if (socketChannel == null) {
+            return;
+        }
+
+        PeerAddress address = PeerAddress.fromSocket(socketChannel.socket());
+        List<String> fixedNetwork = Settings.getInstance().getFixedNetwork();
+        if (fixedNetwork != null && !fixedNetwork.isEmpty() && network.ipNotInFixedList(address, fixedNetwork)) {
+            try {
+                LOGGER.debug("Connection discarded from peer {} as not in the fixed network list", address);
+                socketChannel.close();
+            } catch (IOException e) {
+                // IGNORE
+            }
+            return;
+        }
+
+        final Long now = NTP.getTime();
+        Peer newPeer;
+
+        try {
+            if (now == null) {
+                LOGGER.debug("Connection discarded from peer {} due to lack of NTP sync", address);
+                socketChannel.close();
+                return;
+            }
+
+            LOGGER.debug("Connection accepted from peer {}", address);
+
+            newPeer = new Peer(socketChannel);
+            network.addConnectedPeer(newPeer);
+
+        } catch (IOException e) {
+            if (socketChannel.isOpen()) {
+                try {
+                    LOGGER.debug("Connection failed from peer {} while connecting/closing", address);
+                    socketChannel.close();
+                } catch (IOException ce) {
+                    // Couldn't close?
+                }
+            }
+            return;
+        }
+
+        network.onPeerReady(newPeer);
+    }
+}

src/main/java/org/qortal/network/task/ChannelReadTask.java

@@ -0,0 +1,49 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+import java.io.IOException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+
+public class ChannelReadTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(ChannelReadTask.class);
+
+    private final SocketChannel socketChannel;
+    private final Peer peer;
+    private final String name;
+
+    public ChannelReadTask(SocketChannel socketChannel, Peer peer) {
+        this.socketChannel = socketChannel;
+        this.peer = peer;
+        this.name = "ChannelReadTask::" + peer;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        try {
+            peer.readChannel();
+
+            Network.getInstance().setInterestOps(socketChannel, SelectionKey.OP_READ);
+        } catch (IOException e) {
+            if (e.getMessage() != null && e.getMessage().toLowerCase().contains("connection reset")) {
+                peer.disconnect("Connection reset");
+                return;
+            }
+
+            LOGGER.trace("[{}] Network thread {} encountered I/O error: {}", peer.getPeerConnectionId(),
+                    Thread.currentThread().getId(), e.getMessage(), e);
+            peer.disconnect("I/O error");
+        }
+    }
+}

src/main/java/org/qortal/network/task/ChannelWriteTask.java

@@ -0,0 +1,52 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+import java.io.IOException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+
+public class ChannelWriteTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(ChannelWriteTask.class);
+
+    private final SocketChannel socketChannel;
+    private final Peer peer;
+    private final String name;
+
+    public ChannelWriteTask(SocketChannel socketChannel, Peer peer) {
+        this.socketChannel = socketChannel;
+        this.peer = peer;
+        this.name = "ChannelWriteTask::" + peer;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        try {
+            boolean isSocketClogged = peer.writeChannel();
+
+            // Tell Network that we've finished
+            Network.getInstance().notifyChannelNotWriting(socketChannel);
+
+            if (isSocketClogged)
+                Network.getInstance().setInterestOps(this.socketChannel, SelectionKey.OP_WRITE);
+        } catch (IOException e) {
+            if (e.getMessage() != null && e.getMessage().toLowerCase().contains("connection reset")) {
+                peer.disconnect("Connection reset");
+                return;
+            }
+
+            LOGGER.trace("[{}] Network thread {} encountered I/O error: {}", peer.getPeerConnectionId(),
+                    Thread.currentThread().getId(), e.getMessage(), e);
+            peer.disconnect("I/O error");
+        }
+    }
+}

src/main/java/org/qortal/network/task/MessageTask.java

@@ -0,0 +1,28 @@
+package org.qortal.network.task;
+
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.network.message.Message;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+public class MessageTask implements Task {
+    private final Peer peer;
+    private final Message nextMessage;
+    private final String name;
+
+    public MessageTask(Peer peer, Message nextMessage) {
+        this.peer = peer;
+        this.nextMessage = nextMessage;
+        this.name = "MessageTask::" + peer + "::" + nextMessage.getType();
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Network.getInstance().onMessage(peer, nextMessage);
+    }
+}

src/main/java/org/qortal/network/task/PeerConnectTask.java

@@ -0,0 +1,33 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.network.Network;
+import org.qortal.network.Peer;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.MessageType;
+import org.qortal.network.message.PingMessage;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+import org.qortal.utils.NTP;
+
+public class PeerConnectTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(PeerConnectTask.class);
+
+    private final Peer peer;
+    private final String name;
+
+    public PeerConnectTask(Peer peer) {
+        this.peer = peer;
+        this.name = "PeerConnectTask::" + peer;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Network.getInstance().connectPeer(peer);
+    }
+}

src/main/java/org/qortal/network/task/PingTask.java

@@ -0,0 +1,44 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.network.Peer;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.MessageType;
+import org.qortal.network.message.PingMessage;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+import org.qortal.utils.NTP;
+
+public class PingTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(PingTask.class);
+
+    private final Peer peer;
+    private final Long now;
+    private final String name;
+
+    public PingTask(Peer peer, Long now) {
+        this.peer = peer;
+        this.now = now;
+        this.name = "PingTask::" + peer;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        PingMessage pingMessage = new PingMessage();
+        Message message = peer.getResponse(pingMessage);
+
+        if (message == null || message.getType() != MessageType.PING) {
+            LOGGER.debug("[{}] Didn't receive reply from {} for PING ID {}",
+                    peer.getPeerConnectionId(), peer, pingMessage.getId());
+            peer.disconnect("no ping received");
+            return;
+        }
+
+        peer.setLastPing(NTP.getTime() - now);
+    }
+}

src/main/java/org/qortal/settings/Settings.java

@@ -26,6 +26,8 @@ import org.qortal.controller.arbitrary.ArbitraryDataStorageManager.*;
 import org.qortal.crosschain.Bitcoin.BitcoinNet;
 import org.qortal.crosschain.Litecoin.LitecoinNet;
 import org.qortal.crosschain.Dogecoin.DogecoinNet;
+import org.qortal.crosschain.Digibyte.DigibyteNet;
+import org.qortal.crosschain.Ravencoin.RavencoinNet;
 import org.qortal.utils.EnumUtils;
 
 // All properties to be converted to JSON via JAXB
@@ -222,6 +224,8 @@ public class Settings {
 	private BitcoinNet bitcoinNet = BitcoinNet.MAIN;
 	private LitecoinNet litecoinNet = LitecoinNet.MAIN;
 	private DogecoinNet dogecoinNet = DogecoinNet.MAIN;
+	private DigibyteNet digibyteNet = DigibyteNet.MAIN;
+	private RavencoinNet ravencoinNet = RavencoinNet.MAIN;
 	// Also crosschain-related:
 	/** Whether to show SysTray pop-up notifications when trade-bot entries change state */
 	private boolean tradebotSystrayEnabled = false;
@@ -680,6 +684,14 @@ public class Settings {
 		return this.dogecoinNet;
 	}
 
+	public DigibyteNet getDigibyteNet() {
+		return this.digibyteNet;
+	}
+
+	public RavencoinNet getRavencoinNet() {
+		return this.ravencoinNet;
+	}
+
 	public boolean isTradebotSystrayEnabled() {
 		return this.tradebotSystrayEnabled;
 	}

src/main/java/org/qortal/transaction/BuyNameTransaction.java

@@ -114,7 +114,7 @@ public class BuyNameTransaction extends Transaction {
 	public void process() throws DataException {
 		// Buy Name
 		Name name = new Name(this.repository, this.buyNameTransactionData.getName());
-		name.buy(this.buyNameTransactionData);
+		name.buy(this.buyNameTransactionData, true);
 
 		// Save transaction with updated "name reference" pointing to previous transaction that changed name
 		this.repository.getTransactionRepository().save(this.buyNameTransactionData);

src/main/java/org/qortal/utils/ExecuteProduceConsume.java

@@ -28,7 +28,6 @@ public abstract class ExecuteProduceConsume implements Runnable {
 
 	private final String className;
 	private final Logger logger;
-	private final boolean isLoggerTraceEnabled;
 
 	protected ExecutorService executor;
 
@@ -43,12 +42,12 @@ public abstract class ExecuteProduceConsume implements Runnable {
 	private volatile int tasksConsumed = 0;
 	private volatile int spawnFailures = 0;
 
+	/** Whether a new thread has already been spawned and is waiting to start. Used to prevent spawning multiple new threads. */
 	private volatile boolean hasThreadPending = false;
 
 	public ExecuteProduceConsume(ExecutorService executor) {
 		this.className = this.getClass().getSimpleName();
 		this.logger = LogManager.getLogger(this.getClass());
-		this.isLoggerTraceEnabled = this.logger.isTraceEnabled();
 
 		this.executor = executor;
 	}
@@ -98,15 +97,14 @@ public abstract class ExecuteProduceConsume implements Runnable {
 	 */
 	protected abstract Task produceTask(boolean canBlock) throws InterruptedException;
 
-	@FunctionalInterface
 	public interface Task {
-		public abstract void perform() throws InterruptedException;
+		String getName();
+		void perform() throws InterruptedException;
 	}
 
 	@Override
 	public void run() {
-		if (this.isLoggerTraceEnabled)
-			Thread.currentThread().setName(this.className + "-" + Thread.currentThread().getId());
+		Thread.currentThread().setName(this.className + "-" + Thread.currentThread().getId());
 
 		boolean wasThreadPending;
 		synchronized (this) {
@@ -114,25 +112,19 @@ public abstract class ExecuteProduceConsume implements Runnable {
 			if (this.activeThreadCount > this.greatestActiveThreadCount)
 				this.greatestActiveThreadCount = this.activeThreadCount;
 
-			if (this.isLoggerTraceEnabled) {
-				this.logger.trace(() -> String.format("[%d] started, hasThreadPending was: %b, activeThreadCount now: %d",
-						Thread.currentThread().getId(), this.hasThreadPending, this.activeThreadCount));
-			}
+			this.logger.trace(() -> String.format("[%d] started, hasThreadPending was: %b, activeThreadCount now: %d",
+					Thread.currentThread().getId(), this.hasThreadPending, this.activeThreadCount));
 
 			// Defer clearing hasThreadPending to prevent unnecessary threads waiting to produce...
 			wasThreadPending = this.hasThreadPending;
 		}
 
 		try {
-			// It's possible this might need to become a class instance private volatile
-			boolean canBlock = false;
-
 			while (!Thread.currentThread().isInterrupted()) {
 				Task task = null;
+				String taskType;
 
-				if (this.isLoggerTraceEnabled) {
-					this.logger.trace(() -> String.format("[%d] waiting to produce...", Thread.currentThread().getId()));
-				}
+				this.logger.trace(() -> String.format("[%d] waiting to produce...", Thread.currentThread().getId()));
 
 				synchronized (this) {
 					if (wasThreadPending) {
@@ -141,13 +133,13 @@ public abstract class ExecuteProduceConsume implements Runnable {
 						wasThreadPending = false;
 					}
 
-					final boolean lambdaCanIdle = canBlock;
-					if (this.isLoggerTraceEnabled) {
-						this.logger.trace(() -> String.format("[%d] producing, activeThreadCount: %d, consumerCount: %d, canBlock is %b...",
-								Thread.currentThread().getId(), this.activeThreadCount, this.consumerCount, lambdaCanIdle));
-					}
+					// If we're the only non-consuming thread - producer can afford to block this round
+					boolean canBlock = this.activeThreadCount - this.consumerCount <= 1;
 
-					final long beforeProduce = isLoggerTraceEnabled ? System.currentTimeMillis() : 0;
+					this.logger.trace(() -> String.format("[%d] producing... [activeThreadCount: %d, consumerCount: %d, canBlock: %b]",
+							Thread.currentThread().getId(), this.activeThreadCount, this.consumerCount, canBlock));
+
+					final long beforeProduce = this.logger.isDebugEnabled() ? System.currentTimeMillis() : 0;
 
 					try {
 						task = produceTask(canBlock);
@@ -158,31 +150,36 @@ public abstract class ExecuteProduceConsume implements Runnable {
 						this.logger.warn(() -> String.format("[%d] exception while trying to produce task", Thread.currentThread().getId()), e);
 					}
 
-					if (this.isLoggerTraceEnabled) {
-						this.logger.trace(() -> String.format("[%d] producing took %dms", Thread.currentThread().getId(), System.currentTimeMillis() - beforeProduce));
+					if (this.logger.isDebugEnabled()) {
+						final long productionPeriod = System.currentTimeMillis() - beforeProduce;
+						taskType = task == null ? "no task" : task.getName();
+
+						this.logger.debug(() -> String.format("[%d] produced [%s] in %dms [canBlock: %b]",
+								Thread.currentThread().getId(),
+								taskType,
+								productionPeriod,
+								canBlock
+						));
+					} else {
+						taskType = null;
 					}
 				}
 
 				if (task == null)
 					synchronized (this) {
-						if (this.isLoggerTraceEnabled) {
-							this.logger.trace(() -> String.format("[%d] no task, activeThreadCount: %d, consumerCount: %d",
-									Thread.currentThread().getId(), this.activeThreadCount, this.consumerCount));
-						}
+						this.logger.trace(() -> String.format("[%d] no task, activeThreadCount: %d, consumerCount: %d",
+								Thread.currentThread().getId(), this.activeThreadCount, this.consumerCount));
 
-						if (this.activeThreadCount > this.consumerCount + 1) {
+						// If we have an excess of non-consuming threads then we can exit
+						if (this.activeThreadCount - this.consumerCount > 1) {
 							--this.activeThreadCount;
-							if (this.isLoggerTraceEnabled) {
-								this.logger.trace(() -> String.format("[%d] ending, activeThreadCount now: %d",
-										Thread.currentThread().getId(), this.activeThreadCount));
-							}
+
+							this.logger.trace(() -> String.format("[%d] ending, activeThreadCount now: %d",
+									Thread.currentThread().getId(), this.activeThreadCount));
 
 							return;
 						}
 
-						// We're the last surviving thread - producer can afford to block next round
-						canBlock = true;
-
 						continue;
 					}
 
@@ -192,16 +189,13 @@ public abstract class ExecuteProduceConsume implements Runnable {
 					++this.tasksProduced;
 					++this.consumerCount;
 
-					if (this.isLoggerTraceEnabled) {
-						this.logger.trace(() -> String.format("[%d] hasThreadPending: %b, activeThreadCount: %d, consumerCount now: %d",
-								Thread.currentThread().getId(), this.hasThreadPending, this.activeThreadCount, this.consumerCount));
-					}
+					this.logger.trace(() -> String.format("[%d] hasThreadPending: %b, activeThreadCount: %d, consumerCount now: %d",
+							Thread.currentThread().getId(), this.hasThreadPending, this.activeThreadCount, this.consumerCount));
 
 					// If we have no thread pending and no excess of threads then we should spawn a fresh thread
-					if (!this.hasThreadPending && this.activeThreadCount <= this.consumerCount + 1) {
-						if (this.isLoggerTraceEnabled) {
-							this.logger.trace(() -> String.format("[%d] spawning another thread", Thread.currentThread().getId()));
-						}
+					if (!this.hasThreadPending && this.activeThreadCount == this.consumerCount) {
+						this.logger.trace(() -> String.format("[%d] spawning another thread", Thread.currentThread().getId()));
+
 						this.hasThreadPending = true;
 
 						try {
@@ -209,21 +203,19 @@ public abstract class ExecuteProduceConsume implements Runnable {
 						} catch (RejectedExecutionException e) {
 							++this.spawnFailures;
 							this.hasThreadPending = false;
-							if (this.isLoggerTraceEnabled) {
-								this.logger.trace(() -> String.format("[%d] failed to spawn another thread", Thread.currentThread().getId()));
-							}
+
+							this.logger.trace(() -> String.format("[%d] failed to spawn another thread", Thread.currentThread().getId()));
+
 							this.onSpawnFailure();
 						}
 					} else {
-						if (this.isLoggerTraceEnabled) {
-							this.logger.trace(() -> String.format("[%d] NOT spawning another thread", Thread.currentThread().getId()));
-						}
+						this.logger.trace(() -> String.format("[%d] NOT spawning another thread", Thread.currentThread().getId()));
 					}
 				}
 
-				if (this.isLoggerTraceEnabled) {
-					this.logger.trace(() -> String.format("[%d] performing task...", Thread.currentThread().getId()));
-				}
+				this.logger.trace(() -> String.format("[%d] consuming [%s] task...", Thread.currentThread().getId(), taskType));
+
+				final long beforePerform = this.logger.isDebugEnabled() ? System.currentTimeMillis() : 0;
 
 				try {
 					task.perform(); // This can block for a while
@@ -231,29 +223,25 @@ public abstract class ExecuteProduceConsume implements Runnable {
 					// We're in shutdown situation so exit
 					Thread.currentThread().interrupt();
 				} catch (Exception e) {
-					this.logger.warn(() -> String.format("[%d] exception while performing task", Thread.currentThread().getId()), e);
+					this.logger.warn(() -> String.format("[%d] exception while consuming task", Thread.currentThread().getId()), e);
 				}
 
-				if (this.isLoggerTraceEnabled) {
-					this.logger.trace(() -> String.format("[%d] finished task", Thread.currentThread().getId()));
+				if (this.logger.isDebugEnabled()) {
+					final long productionPeriod = System.currentTimeMillis() - beforePerform;
+
+					this.logger.debug(() -> String.format("[%d] consumed [%s] task in %dms", Thread.currentThread().getId(), taskType, productionPeriod));
 				}
 
 				synchronized (this) {
 					++this.tasksConsumed;
 					--this.consumerCount;
 
-					if (this.isLoggerTraceEnabled) {
-						this.logger.trace(() -> String.format("[%d] consumerCount now: %d",
-								Thread.currentThread().getId(), this.consumerCount));
-					}
-
-					// Quicker, non-blocking produce next round
-					canBlock = false;
+					this.logger.trace(() -> String.format("[%d] consumerCount now: %d",
+							Thread.currentThread().getId(), this.consumerCount));
 				}
 			}
 		} finally {
-			if (this.isLoggerTraceEnabled)
-				Thread.currentThread().setName(this.className);
+			Thread.currentThread().setName(this.className);
 		}
 	}
 

src/test/java/org/qortal/test/EPCTests.java

@@ -13,9 +13,25 @@ import org.junit.Test;
 import org.qortal.utils.ExecuteProduceConsume;
 import org.qortal.utils.ExecuteProduceConsume.StatsSnapshot;
 
+import static org.junit.Assert.fail;
+
 public class EPCTests {
 
-	class RandomEPC extends ExecuteProduceConsume {
+	static class SleepTask implements ExecuteProduceConsume.Task {
+		private static final Random RANDOM = new Random();
+
+		@Override
+		public String getName() {
+			return "SleepTask";
+		}
+
+		@Override
+		public void perform() throws InterruptedException {
+			Thread.sleep(RANDOM.nextInt(500) + 100);
+		}
+	}
+
+	static class RandomEPC extends ExecuteProduceConsume {
 		private final int TASK_PERCENT;
 		private final int PAUSE_PERCENT;
 
@@ -37,9 +53,7 @@ public class EPCTests {
 
 			// Sometimes produce a task
 			if (percent < TASK_PERCENT) {
-				return () -> {
-					Thread.sleep(random.nextInt(500) + 100);
-				};
+				return new SleepTask();
 			} else {
 				// If we don't produce a task, then maybe simulate a pause until work arrives
 				if (canIdle && percent < PAUSE_PERCENT)
@@ -50,45 +64,6 @@ public class EPCTests {
 		}
 	}
 
-	private void testEPC(ExecuteProduceConsume testEPC) throws InterruptedException {
-		final int runTime = 60; // seconds
-		System.out.println(String.format("Testing EPC for %s seconds:", runTime));
-
-		final long start = System.currentTimeMillis();
-		testEPC.start();
-
-		// Status reports every second (bar waiting for synchronization)
-		ScheduledExecutorService statusExecutor = Executors.newSingleThreadScheduledExecutor();
-
-		statusExecutor.scheduleAtFixedRate(() -> {
-			final StatsSnapshot snapshot = testEPC.getStatsSnapshot();
-			final long seconds = (System.currentTimeMillis() - start) / 1000L;
-			System.out.print(String.format("After %d second%s, ", seconds, (seconds != 1 ? "s" : "")));
-			printSnapshot(snapshot);
-		}, 1L, 1L, TimeUnit.SECONDS);
-
-		// Let it run for a minute
-		Thread.sleep(runTime * 1000L);
-		statusExecutor.shutdownNow();
-
-		final long before = System.currentTimeMillis();
-		testEPC.shutdown(30 * 1000);
-		final long after = System.currentTimeMillis();
-
-		System.out.println(String.format("Shutdown took %d milliseconds", after - before));
-
-		final StatsSnapshot snapshot = testEPC.getStatsSnapshot();
-		System.out.print("After shutdown, ");
-		printSnapshot(snapshot);
-	}
-
-	private void printSnapshot(final StatsSnapshot snapshot) {
-		System.out.println(String.format("threads: %d active (%d max, %d exhaustion%s), tasks: %d produced / %d consumed",
-				snapshot.activeThreadCount, snapshot.greatestActiveThreadCount,
-				snapshot.spawnFailures, (snapshot.spawnFailures != 1 ? "s": ""),
-				snapshot.tasksProduced, snapshot.tasksConsumed));
-	}
-
 	@Test
 	public void testRandomEPC() throws InterruptedException {
 		final int TASK_PERCENT = 25; // Produce a task this % of the time
@@ -131,18 +106,39 @@ public class EPCTests {
 
 		final int MAX_PEERS = 20;
 
-		final List<Long> lastPings = new ArrayList<>(Collections.nCopies(MAX_PEERS, System.currentTimeMillis()));
+		final List<Long> lastPingProduced = new ArrayList<>(Collections.nCopies(MAX_PEERS, System.currentTimeMillis()));
 
 		class PingTask implements ExecuteProduceConsume.Task {
 			private final int peerIndex;
+			private final long lastPing;
+			private final long productionTimestamp;
+			private final String name;
 
-			public PingTask(int peerIndex) {
+			public PingTask(int peerIndex, long lastPing, long productionTimestamp) {
 				this.peerIndex = peerIndex;
+				this.lastPing = lastPing;
+				this.productionTimestamp = productionTimestamp;
+				this.name = "PingTask::[" + this.peerIndex + "]";
+			}
+
+			@Override
+			public String getName() {
+				return name;
 			}
 
 			@Override
 			public void perform() throws InterruptedException {
-				System.out.println("Pinging peer " + peerIndex);
+				long now = System.currentTimeMillis();
+
+				System.out.println(String.format("Pinging peer %d after post-production delay of %dms and ping interval of %dms",
+						peerIndex,
+						now - productionTimestamp,
+						now - lastPing
+				));
+
+				long threshold = now - PING_INTERVAL - PRODUCER_SLEEP_TIME;
+				if (lastPing < threshold)
+					fail("excessive peer ping interval for peer " + peerIndex);
 
 				// At least half the worst case ping round-trip
 				Random random = new Random();
@@ -155,32 +151,73 @@ public class EPCTests {
 		class PingEPC extends ExecuteProduceConsume {
 			@Override
 			protected Task produceTask(boolean canIdle) throws InterruptedException {
-				// If we can idle, then we do, to simulate worst case
-				if (canIdle)
-					Thread.sleep(PRODUCER_SLEEP_TIME);
-
 				// Is there a peer that needs a ping?
 				final long now = System.currentTimeMillis();
-				synchronized (lastPings) {
-					for (int peerIndex = 0; peerIndex < lastPings.size(); ++peerIndex) {
-						long lastPing = lastPings.get(peerIndex);
-
-						if (lastPing < now - PING_INTERVAL - PING_ROUND_TRIP_TIME - PRODUCER_SLEEP_TIME)
-							throw new RuntimeException("excessive peer ping interval for peer " + peerIndex);
+				synchronized (lastPingProduced) {
+					for (int peerIndex = 0; peerIndex < lastPingProduced.size(); ++peerIndex) {
+						long lastPing = lastPingProduced.get(peerIndex);
 
 						if (lastPing < now - PING_INTERVAL) {
-							lastPings.set(peerIndex, System.currentTimeMillis());
-							return new PingTask(peerIndex);
+							lastPingProduced.set(peerIndex, System.currentTimeMillis());
+							return new PingTask(peerIndex, lastPing, now);
 						}
 					}
 				}
 
+				// If we can idle, then we do, to simulate worst case
+				if (canIdle)
+					Thread.sleep(PRODUCER_SLEEP_TIME);
+
 				// No work to do
 				return null;
 			}
 		}
 
+		System.out.println(String.format("Pings should start after %s seconds", PING_INTERVAL));
+
 		testEPC(new PingEPC());
 	}
 
+	private void testEPC(ExecuteProduceConsume testEPC) throws InterruptedException {
+		final int runTime = 60; // seconds
+		System.out.println(String.format("Testing EPC for %s seconds:", runTime));
+
+		final long start = System.currentTimeMillis();
+
+		// Status reports every second (bar waiting for synchronization)
+		ScheduledExecutorService statusExecutor = Executors.newSingleThreadScheduledExecutor();
+
+		statusExecutor.scheduleAtFixedRate(
+				() -> {
+					final StatsSnapshot snapshot = testEPC.getStatsSnapshot();
+					final long seconds = (System.currentTimeMillis() - start) / 1000L;
+					System.out.println(String.format("After %d second%s, %s", seconds, seconds != 1 ? "s" : "", formatSnapshot(snapshot)));
+				},
+				0L, 1L, TimeUnit.SECONDS
+		);
+
+		testEPC.start();
+
+		// Let it run for a minute
+		Thread.sleep(runTime * 1000L);
+		statusExecutor.shutdownNow();
+
+		final long before = System.currentTimeMillis();
+		testEPC.shutdown(30 * 1000);
+		final long after = System.currentTimeMillis();
+
+		System.out.println(String.format("Shutdown took %d milliseconds", after - before));
+
+		final StatsSnapshot snapshot = testEPC.getStatsSnapshot();
+		System.out.println("After shutdown, " + formatSnapshot(snapshot));
+	}
+
+	private String formatSnapshot(StatsSnapshot snapshot) {
+		return String.format("threads: %d active (%d max, %d exhaustion%s), tasks: %d produced / %d consumed",
+				snapshot.activeThreadCount, snapshot.greatestActiveThreadCount,
+				snapshot.spawnFailures, (snapshot.spawnFailures != 1 ? "s": ""),
+				snapshot.tasksProduced, snapshot.tasksConsumed
+		);
+	}
+
 }

src/test/java/org/qortal/test/crosschain/DigibyteTests.java

@@ -0,0 +1,115 @@
+package org.qortal.test.crosschain;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.store.BlockStoreException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Digibyte;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.repository.DataException;
+import org.qortal.test.common.Common;
+
+public class DigibyteTests extends Common {
+
+	private Digibyte digibyte;
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings(); // TestNet3
+		digibyte = Digibyte.getInstance();
+	}
+
+	@After
+	public void afterTest() {
+		Digibyte.resetForTesting();
+		digibyte = null;
+	}
+
+	@Test
+	public void testGetMedianBlockTime() throws BlockStoreException, ForeignBlockchainException {
+		long before = System.currentTimeMillis();
+		System.out.println(String.format("Digibyte median blocktime: %d", digibyte.getMedianBlockTime()));
+		long afterFirst = System.currentTimeMillis();
+
+		System.out.println(String.format("Digibyte median blocktime: %d", digibyte.getMedianBlockTime()));
+		long afterSecond = System.currentTimeMillis();
+
+		long firstPeriod = afterFirst - before;
+		long secondPeriod = afterSecond - afterFirst;
+
+		System.out.println(String.format("1st call: %d ms, 2nd call: %d ms", firstPeriod, secondPeriod));
+
+		assertTrue("2nd call should be quicker than 1st", secondPeriod < firstPeriod);
+		assertTrue("2nd call should take less than 5 seconds", secondPeriod < 5000L);
+	}
+
+	@Test
+	@Ignore(value = "Doesn't work, to be fixed later")
+	public void testFindHtlcSecret() throws ForeignBlockchainException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+		byte[] secret = BitcoinyHTLC.findHtlcSecret(digibyte, p2shAddress);
+
+		assertNotNull("secret not found", secret);
+		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
+	}
+
+	@Test
+	@Ignore(value = "No testnet nodes available, so we can't regularly test buildSpend yet")
+	public void testBuildSpend() {
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		String recipient = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+		long amount = 1000L;
+
+		Transaction transaction = digibyte.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+
+		// Check spent key caching doesn't affect outcome
+
+		transaction = digibyte.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+	}
+
+	@Test
+	public void testGetWalletBalance() {
+		String xprv58 = "xpub661MyMwAqRbcEnabTLX5uebYcsE3uG5y7ve9jn1VK8iY1MaU3YLoLJEe8sTu2YVav5Zka5qf2dmMssfxmXJTqZnazZL2kL7M2tNKwEoC34R";
+
+		Long balance = digibyte.getWalletBalance(xprv58);
+
+		assertNotNull(balance);
+
+		System.out.println(digibyte.format(balance));
+
+		// Check spent key caching doesn't affect outcome
+
+		Long repeatBalance = digibyte.getWalletBalance(xprv58);
+
+		assertNotNull(repeatBalance);
+
+		System.out.println(digibyte.format(repeatBalance));
+
+		assertEquals(balance, repeatBalance);
+	}
+
+	@Test
+	public void testGetUnusedReceiveAddress() throws ForeignBlockchainException {
+		String xprv58 = "xpub661MyMwAqRbcEnabTLX5uebYcsE3uG5y7ve9jn1VK8iY1MaU3YLoLJEe8sTu2YVav5Zka5qf2dmMssfxmXJTqZnazZL2kL7M2tNKwEoC34R";
+
+		String address = digibyte.getUnusedReceiveAddress(xprv58);
+
+		assertNotNull(address);
+
+		System.out.println(address);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/RavencoinTests.java

@@ -0,0 +1,115 @@
+package org.qortal.test.crosschain;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.store.BlockStoreException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Ravencoin;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.repository.DataException;
+import org.qortal.test.common.Common;
+
+public class RavencoinTests extends Common {
+
+	private Ravencoin ravencoin;
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings(); // TestNet3
+		ravencoin = Ravencoin.getInstance();
+	}
+
+	@After
+	public void afterTest() {
+		Ravencoin.resetForTesting();
+		ravencoin = null;
+	}
+
+	@Test
+	public void testGetMedianBlockTime() throws BlockStoreException, ForeignBlockchainException {
+		long before = System.currentTimeMillis();
+		System.out.println(String.format("Ravencoin median blocktime: %d", ravencoin.getMedianBlockTime()));
+		long afterFirst = System.currentTimeMillis();
+
+		System.out.println(String.format("Ravencoin median blocktime: %d", ravencoin.getMedianBlockTime()));
+		long afterSecond = System.currentTimeMillis();
+
+		long firstPeriod = afterFirst - before;
+		long secondPeriod = afterSecond - afterFirst;
+
+		System.out.println(String.format("1st call: %d ms, 2nd call: %d ms", firstPeriod, secondPeriod));
+
+		assertTrue("2nd call should be quicker than 1st", secondPeriod < firstPeriod);
+		assertTrue("2nd call should take less than 5 seconds", secondPeriod < 5000L);
+	}
+
+	@Test
+	@Ignore(value = "Doesn't work, to be fixed later")
+	public void testFindHtlcSecret() throws ForeignBlockchainException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+		byte[] secret = BitcoinyHTLC.findHtlcSecret(ravencoin, p2shAddress);
+
+		assertNotNull("secret not found", secret);
+		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
+	}
+
+	@Test
+	@Ignore(value = "No testnet nodes available, so we can't regularly test buildSpend yet")
+	public void testBuildSpend() {
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		String recipient = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+		long amount = 1000L;
+
+		Transaction transaction = ravencoin.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+
+		// Check spent key caching doesn't affect outcome
+
+		transaction = ravencoin.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+	}
+
+	@Test
+	public void testGetWalletBalance() {
+		String xprv58 = "xpub661MyMwAqRbcEt3Ge1wNmkagyb1J7yTQu4Kquvy77Ycg2iPoh7Urg8s9Jdwp7YmrqGkDKJpUVjsZXSSsQgmAVUC17ZVQQeoWMzm7vDTt1y7";
+
+		Long balance = ravencoin.getWalletBalance(xprv58);
+
+		assertNotNull(balance);
+
+		System.out.println(ravencoin.format(balance));
+
+		// Check spent key caching doesn't affect outcome
+
+		Long repeatBalance = ravencoin.getWalletBalance(xprv58);
+
+		assertNotNull(repeatBalance);
+
+		System.out.println(ravencoin.format(repeatBalance));
+
+		assertEquals(balance, repeatBalance);
+	}
+
+	@Test
+	public void testGetUnusedReceiveAddress() throws ForeignBlockchainException {
+		String xprv58 = "xpub661MyMwAqRbcEt3Ge1wNmkagyb1J7yTQu4Kquvy77Ycg2iPoh7Urg8s9Jdwp7YmrqGkDKJpUVjsZXSSsQgmAVUC17ZVQQeoWMzm7vDTt1y7";
+
+		String address = ravencoin.getUnusedReceiveAddress(xprv58);
+
+		assertNotNull(address);
+
+		System.out.println(address);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/digibytev3/DigibyteACCTv3Tests.java

@@ -0,0 +1,769 @@
+package org.qortal.test.crosschain.digibytev3;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.Account;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.block.Block;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crosschain.DigibyteACCTv3;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.utils.Amounts;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+
+import static org.junit.Assert.*;
+
+public class DigibyteACCTv3Tests extends Common {
+
+	public static final byte[] secretA = "This string is exactly 32 bytes!".getBytes();
+	public static final byte[] hashOfSecretA = Crypto.hash160(secretA); // daf59884b4d1aec8c1b17102530909ee43c0151a
+	public static final byte[] digibytePublicKeyHash = HashCode.fromString("bb00bb11bb22bb33bb44bb55bb66bb77bb88bb99").asBytes();
+	public static final int tradeTimeout = 20; // blocks
+	public static final long redeemAmount = 80_40200000L;
+	public static final long fundingAmount = 123_45600000L;
+	public static final long digibyteAmount = 864200L; // 0.00864200 DGB
+
+	private static final Random RANDOM = new Random();
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testCompile() {
+		PrivateKeyAccount tradeAccount = createTradeAccount(null);
+
+		byte[] creationBytes = DigibyteACCTv3.buildQortalAT(tradeAccount.getAddress(), digibytePublicKeyHash, redeemAmount, digibyteAmount, tradeTimeout);
+		assertNotNull(creationBytes);
+
+		System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+	}
+
+	@Test
+	public void testDeploy() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			long expectedBalance = deployersInitialBalance - fundingAmount - deployAtTransaction.getTransactionData().getFee();
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = fundingAmount;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			expectedBalance = deployersInitialBalance;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = 0;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancel() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Send creator's address to AT, instead of typical partner's address
+			byte[] messageData = DigibyteACCTv3.getInstance().buildCancelMessage(deployer.getAddress());
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+
+			// Check balances
+			long expectedMinimumBalance = deployersPostDeploymentBalance;
+			long expectedMaximumBalance = deployersInitialBalance - deployAtFee - messageFee;
+
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+			assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance - messageFee;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancelInvalidLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Instead of sending creator's address to AT, send too-short/invalid message
+			byte[] messageData = new byte[7];
+			RANDOM.nextBytes(messageData);
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			// As message is too short, it will be padded to 32bytes but cancel code doesn't care about message content, so should be ok
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testTradingInfoProcessing() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should be in TRADE mode
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check hashOfSecretA was extracted correctly
+			assertTrue(Arrays.equals(hashOfSecretA, tradeData.hashOfSecretA));
+
+			// Check trade partner Qortal address was extracted correctly
+			assertEquals(partner.getAddress(), tradeData.qortalPartnerAddress);
+
+			// Check trade partner's digibyte PKH was extracted correctly
+			assertTrue(Arrays.equals(digibytePublicKeyHash, tradeData.partnerForeignPKH));
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	// TEST SENDING TRADING INFO BUT NOT FROM AT CREATOR (SHOULD BE IGNORED)
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectTradeSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT BUT NOT FROM AT CREATOR
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			BlockUtils.mintBlock(repository);
+
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-initial-payout balance incorrect", expectedBalance, actualBalance);
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should still be in OFFER mode
+			assertEquals(AcctMode.OFFERING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testAutomaticTradeRefund() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			// Check refund
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REFUNDED mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REFUNDED, tradeData.mode);
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account
+			messageData = DigibyteACCTv3.buildRedeemMessage(secretA,  partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REDEEMED mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REDEEMED, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() + redeemAmount;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Orphan redeem
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Check AT state
+			ATStateData postOrphanAtStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertTrue("AT states mismatch", Arrays.equals(preRedeemAtStateData.getStateData(), postOrphanAtStateData.getStateData()));
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretIncorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, but from wrong account
+			messageData = DigibyteACCTv3.buildRedeemMessage(secretA, partner.getAddress());
+			messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send incorrect secret to AT, from correct account
+			byte[] wrongSecret = new byte[32];
+			RANDOM.nextBytes(wrongSecret);
+			messageData = DigibyteACCTv3.buildRedeemMessage(wrongSecret, partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSenderInvalidMessageLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = DigibyteACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = DigibyteACCTv3.buildTradeMessage(partner.getAddress(), digibytePublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account, but missing receive address, hence incorrect length
+			messageData = Bytes.concat(secretA);
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should be in TRADING mode
+			CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testDescribeDeployed() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			List<ATData> executableAts = repository.getATRepository().getAllExecutableATs();
+
+			for (ATData atData : executableAts) {
+				String atAddress = atData.getATAddress();
+				byte[] codeBytes = atData.getCodeBytes();
+				byte[] codeHash = Crypto.digest(codeBytes);
+
+				System.out.println(String.format("%s: code length: %d byte%s, code hash: %s",
+						atAddress,
+						codeBytes.length,
+						(codeBytes.length != 1 ? "s": ""),
+						HashCode.fromBytes(codeHash)));
+
+				// Not one of ours?
+				if (!Arrays.equals(codeHash, DigibyteACCTv3.CODE_BYTES_HASH))
+					continue;
+
+				describeAt(repository, atAddress);
+			}
+		}
+	}
+
+	private int calcTestLockTimeA(long messageTimestamp) {
+		return (int) (messageTimestamp / 1000L + tradeTimeout * 60);
+	}
+
+	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, String tradeAddress) throws DataException {
+		byte[] creationBytes = DigibyteACCTv3.buildQortalAT(tradeAddress, digibytePublicKeyHash, redeemAmount, digibyteAmount, tradeTimeout);
+
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = deployer.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", deployer.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		String name = "QORT-DGB cross-chain trade";
+		String description = String.format("Qortal-Digibyte cross-chain trade");
+		String atType = "ACCT";
+		String tags = "QORT-DGB ACCT";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, deployer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, deployAtTransactionData, deployer);
+
+		return deployAtTransaction;
+	}
+
+	private MessageTransaction sendMessage(Repository repository, PrivateKeyAccount sender, byte[] data, String recipient) throws DataException {
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = sender.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", sender.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		int version = 4;
+		int nonce = 0;
+		long amount = 0;
+		Long assetId = null; // because amount is zero
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, sender.getPublicKey(), fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, recipient, amount, assetId, data, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		fee = messageTransaction.calcRecommendedFee();
+		messageTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, messageTransactionData, sender);
+
+		return messageTransaction;
+	}
+
+	private void checkTradeRefund(Repository repository, Account deployer, long deployersInitialBalance, long deployAtFee) throws DataException {
+		long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+		int refundTimeout = tradeTimeout / 2 + 1; // close enough
+
+		// AT should automatically refund deployer after 'refundTimeout' blocks
+		for (int blockCount = 0; blockCount <= refundTimeout; ++blockCount)
+			BlockUtils.mintBlock(repository);
+
+		// We don't bother to exactly calculate QORT spent running AT for several blocks, but we do know the expected range
+		long expectedMinimumBalance = deployersPostDeploymentBalance;
+		long expectedMaximumBalance = deployersInitialBalance - deployAtFee;
+
+		long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+		assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+		assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+	}
+
+	private void describeAt(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		CrossChainTradeData tradeData = DigibyteACCTv3.getInstance().populateTradeData(repository, atData);
+
+		Function<Long, String> epochMilliFormatter = (timestamp) -> LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneOffset.UTC).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM));
+		int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
+
+		System.out.print(String.format("%s:\n"
+				+ "\tmode: %s\n"
+				+ "\tcreator: %s,\n"
+				+ "\tcreation timestamp: %s,\n"
+				+ "\tcurrent balance: %s QORT,\n"
+				+ "\tis finished: %b,\n"
+				+ "\tredeem payout: %s QORT,\n"
+				+ "\texpected digibyte: %s DGB,\n"
+				+ "\tcurrent block height: %d,\n",
+				tradeData.qortalAtAddress,
+				tradeData.mode,
+				tradeData.qortalCreator,
+				epochMilliFormatter.apply(tradeData.creationTimestamp),
+				Amounts.prettyAmount(tradeData.qortBalance),
+				atData.getIsFinished(),
+				Amounts.prettyAmount(tradeData.qortAmount),
+				Amounts.prettyAmount(tradeData.expectedForeignAmount),
+				currentBlockHeight));
+
+		if (tradeData.mode != AcctMode.OFFERING && tradeData.mode != AcctMode.CANCELLED) {
+			System.out.println(String.format("\trefund timeout: %d minutes,\n"
+					+ "\trefund height: block %d,\n"
+					+ "\tHASH160 of secret-A: %s,\n"
+					+ "\tDigibyte P2SH-A nLockTime: %d (%s),\n"
+					+ "\ttrade partner: %s\n"
+					+ "\tpartner's receiving address: %s",
+					tradeData.refundTimeout,
+					tradeData.tradeRefundHeight,
+					HashCode.fromBytes(tradeData.hashOfSecretA).toString().substring(0, 40),
+					tradeData.lockTimeA, epochMilliFormatter.apply(tradeData.lockTimeA * 1000L),
+					tradeData.qortalPartnerAddress,
+					tradeData.qortalPartnerReceivingAddress));
+		}
+	}
+
+	private PrivateKeyAccount createTradeAccount(Repository repository) {
+		// We actually use a known test account with funds to avoid PoW compute
+		return Common.getTestAccount(repository, "alice");
+	}
+
+}

src/test/java/org/qortal/test/crosschain/ravencoinv3/RavencoinACCTv3Tests.java

@@ -0,0 +1,769 @@
+package org.qortal.test.crosschain.ravencoinv3;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.Account;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.block.Block;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crosschain.RavencoinACCTv3;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.utils.Amounts;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+
+import static org.junit.Assert.*;
+
+public class RavencoinACCTv3Tests extends Common {
+
+	public static final byte[] secretA = "This string is exactly 32 bytes!".getBytes();
+	public static final byte[] hashOfSecretA = Crypto.hash160(secretA); // daf59884b4d1aec8c1b17102530909ee43c0151a
+	public static final byte[] ravencoinPublicKeyHash = HashCode.fromString("bb00bb11bb22bb33bb44bb55bb66bb77bb88bb99").asBytes();
+	public static final int tradeTimeout = 20; // blocks
+	public static final long redeemAmount = 80_40200000L;
+	public static final long fundingAmount = 123_45600000L;
+	public static final long ravencoinAmount = 864200L; // 0.00864200 RVN
+
+	private static final Random RANDOM = new Random();
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testCompile() {
+		PrivateKeyAccount tradeAccount = createTradeAccount(null);
+
+		byte[] creationBytes = RavencoinACCTv3.buildQortalAT(tradeAccount.getAddress(), ravencoinPublicKeyHash, redeemAmount, ravencoinAmount, tradeTimeout);
+		assertNotNull(creationBytes);
+
+		System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+	}
+
+	@Test
+	public void testDeploy() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			long expectedBalance = deployersInitialBalance - fundingAmount - deployAtTransaction.getTransactionData().getFee();
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = fundingAmount;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			expectedBalance = deployersInitialBalance;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = 0;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancel() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Send creator's address to AT, instead of typical partner's address
+			byte[] messageData = RavencoinACCTv3.getInstance().buildCancelMessage(deployer.getAddress());
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+
+			// Check balances
+			long expectedMinimumBalance = deployersPostDeploymentBalance;
+			long expectedMaximumBalance = deployersInitialBalance - deployAtFee - messageFee;
+
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+			assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance - messageFee;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancelInvalidLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Instead of sending creator's address to AT, send too-short/invalid message
+			byte[] messageData = new byte[7];
+			RANDOM.nextBytes(messageData);
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			// As message is too short, it will be padded to 32bytes but cancel code doesn't care about message content, so should be ok
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testTradingInfoProcessing() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should be in TRADE mode
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check hashOfSecretA was extracted correctly
+			assertTrue(Arrays.equals(hashOfSecretA, tradeData.hashOfSecretA));
+
+			// Check trade partner Qortal address was extracted correctly
+			assertEquals(partner.getAddress(), tradeData.qortalPartnerAddress);
+
+			// Check trade partner's ravencoin PKH was extracted correctly
+			assertTrue(Arrays.equals(ravencoinPublicKeyHash, tradeData.partnerForeignPKH));
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	// TEST SENDING TRADING INFO BUT NOT FROM AT CREATOR (SHOULD BE IGNORED)
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectTradeSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT BUT NOT FROM AT CREATOR
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			BlockUtils.mintBlock(repository);
+
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-initial-payout balance incorrect", expectedBalance, actualBalance);
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should still be in OFFER mode
+			assertEquals(AcctMode.OFFERING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testAutomaticTradeRefund() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			// Check refund
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REFUNDED mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REFUNDED, tradeData.mode);
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account
+			messageData = RavencoinACCTv3.buildRedeemMessage(secretA,  partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REDEEMED mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REDEEMED, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() + redeemAmount;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Orphan redeem
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Check AT state
+			ATStateData postOrphanAtStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertTrue("AT states mismatch", Arrays.equals(preRedeemAtStateData.getStateData(), postOrphanAtStateData.getStateData()));
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretIncorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, but from wrong account
+			messageData = RavencoinACCTv3.buildRedeemMessage(secretA, partner.getAddress());
+			messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send incorrect secret to AT, from correct account
+			byte[] wrongSecret = new byte[32];
+			RANDOM.nextBytes(wrongSecret);
+			messageData = RavencoinACCTv3.buildRedeemMessage(wrongSecret, partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSenderInvalidMessageLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = RavencoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = RavencoinACCTv3.buildTradeMessage(partner.getAddress(), ravencoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account, but missing receive address, hence incorrect length
+			messageData = Bytes.concat(secretA);
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should be in TRADING mode
+			CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testDescribeDeployed() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			List<ATData> executableAts = repository.getATRepository().getAllExecutableATs();
+
+			for (ATData atData : executableAts) {
+				String atAddress = atData.getATAddress();
+				byte[] codeBytes = atData.getCodeBytes();
+				byte[] codeHash = Crypto.digest(codeBytes);
+
+				System.out.println(String.format("%s: code length: %d byte%s, code hash: %s",
+						atAddress,
+						codeBytes.length,
+						(codeBytes.length != 1 ? "s": ""),
+						HashCode.fromBytes(codeHash)));
+
+				// Not one of ours?
+				if (!Arrays.equals(codeHash, RavencoinACCTv3.CODE_BYTES_HASH))
+					continue;
+
+				describeAt(repository, atAddress);
+			}
+		}
+	}
+
+	private int calcTestLockTimeA(long messageTimestamp) {
+		return (int) (messageTimestamp / 1000L + tradeTimeout * 60);
+	}
+
+	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, String tradeAddress) throws DataException {
+		byte[] creationBytes = RavencoinACCTv3.buildQortalAT(tradeAddress, ravencoinPublicKeyHash, redeemAmount, ravencoinAmount, tradeTimeout);
+
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = deployer.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", deployer.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		String name = "QORT-RVN cross-chain trade";
+		String description = String.format("Qortal-Ravencoin cross-chain trade");
+		String atType = "ACCT";
+		String tags = "QORT-RVN ACCT";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, deployer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, deployAtTransactionData, deployer);
+
+		return deployAtTransaction;
+	}
+
+	private MessageTransaction sendMessage(Repository repository, PrivateKeyAccount sender, byte[] data, String recipient) throws DataException {
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = sender.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", sender.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		int version = 4;
+		int nonce = 0;
+		long amount = 0;
+		Long assetId = null; // because amount is zero
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, sender.getPublicKey(), fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, recipient, amount, assetId, data, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		fee = messageTransaction.calcRecommendedFee();
+		messageTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, messageTransactionData, sender);
+
+		return messageTransaction;
+	}
+
+	private void checkTradeRefund(Repository repository, Account deployer, long deployersInitialBalance, long deployAtFee) throws DataException {
+		long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+		int refundTimeout = tradeTimeout / 2 + 1; // close enough
+
+		// AT should automatically refund deployer after 'refundTimeout' blocks
+		for (int blockCount = 0; blockCount <= refundTimeout; ++blockCount)
+			BlockUtils.mintBlock(repository);
+
+		// We don't bother to exactly calculate QORT spent running AT for several blocks, but we do know the expected range
+		long expectedMinimumBalance = deployersPostDeploymentBalance;
+		long expectedMaximumBalance = deployersInitialBalance - deployAtFee;
+
+		long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+		assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+		assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+	}
+
+	private void describeAt(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		CrossChainTradeData tradeData = RavencoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+		Function<Long, String> epochMilliFormatter = (timestamp) -> LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneOffset.UTC).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM));
+		int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
+
+		System.out.print(String.format("%s:\n"
+				+ "\tmode: %s\n"
+				+ "\tcreator: %s,\n"
+				+ "\tcreation timestamp: %s,\n"
+				+ "\tcurrent balance: %s QORT,\n"
+				+ "\tis finished: %b,\n"
+				+ "\tredeem payout: %s QORT,\n"
+				+ "\texpected ravencoin: %s RVN,\n"
+				+ "\tcurrent block height: %d,\n",
+				tradeData.qortalAtAddress,
+				tradeData.mode,
+				tradeData.qortalCreator,
+				epochMilliFormatter.apply(tradeData.creationTimestamp),
+				Amounts.prettyAmount(tradeData.qortBalance),
+				atData.getIsFinished(),
+				Amounts.prettyAmount(tradeData.qortAmount),
+				Amounts.prettyAmount(tradeData.expectedForeignAmount),
+				currentBlockHeight));
+
+		if (tradeData.mode != AcctMode.OFFERING && tradeData.mode != AcctMode.CANCELLED) {
+			System.out.println(String.format("\trefund timeout: %d minutes,\n"
+					+ "\trefund height: block %d,\n"
+					+ "\tHASH160 of secret-A: %s,\n"
+					+ "\tRavencoin P2SH-A nLockTime: %d (%s),\n"
+					+ "\ttrade partner: %s\n"
+					+ "\tpartner's receiving address: %s",
+					tradeData.refundTimeout,
+					tradeData.tradeRefundHeight,
+					HashCode.fromBytes(tradeData.hashOfSecretA).toString().substring(0, 40),
+					tradeData.lockTimeA, epochMilliFormatter.apply(tradeData.lockTimeA * 1000L),
+					tradeData.qortalPartnerAddress,
+					tradeData.qortalPartnerReceivingAddress));
+		}
+	}
+
+	private PrivateKeyAccount createTradeAccount(Repository repository) {
+		// We actually use a known test account with funds to avoid PoW compute
+		return Common.getTestAccount(repository, "alice");
+	}
+
+}

src/test/java/org/qortal/test/network/OnlineAccountsTests.java

@@ -29,7 +29,7 @@ public class OnlineAccountsTests {
 
 
     @Test
-    public void testGetOnlineAccountsV2() throws Message.MessageException {
+    public void testGetOnlineAccountsV2() throws MessageException {
         List<OnlineAccountData> onlineAccountsOut = generateOnlineAccounts(false);
 
         Message messageOut = new GetOnlineAccountsV2Message(onlineAccountsOut);
@@ -58,7 +58,7 @@ public class OnlineAccountsTests {
     }
 
     @Test
-    public void testOnlineAccountsV2() throws Message.MessageException {
+    public void testOnlineAccountsV2() throws MessageException {
         List<OnlineAccountData> onlineAccountsOut = generateOnlineAccounts(true);
 
         Message messageOut = new OnlineAccountsV2Message(onlineAccountsOut);