Bump version to 1.7.0

This reverts commit 8c325f3a8a.

.gitignore

@@ -1,6 +1,8 @@
 /db*
+/lists/
 /bin/
 /target/
+/qortal-backup/
 /log.txt.*
 /arbitrary*
 /Qortal-BTC*
@@ -14,13 +16,13 @@
 /settings.json
 /testnet*
 /settings*.json
-/testchain.json
-/run-testnet.sh
+/testchain*.json
+/run-testnet*.sh
 /.idea
 /qortal.iml
 .DS_Store
 /src/main/resources/resources
-/src/main/resources/log*.properties
 /*.jar
 /run.pid
 /run.log
+/WindowsInstaller/Install Files/qortal.jar

WindowsInstaller/Qortal.aip

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <DOCUMENT Type="Advanced Installer" CreateVersion="14.9" version="18.2" Modules="enterprise" RootPath="." Language="en_GB" Id="{713E21E0-28FC-422F-8A95-823D01A5F80B}">
   <COMPONENT cid="caphyon.advinst.msicomp.MsiPropsComponent">
     <ROW Property="AI_BITMAP_DISPLAY_MODE" Value="0"/>
@@ -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:{75ABAC87-9F88-4229-A7D5-DE07F082566D} 1049:{42997A88-BD5D-4829-9FFD-96D0F14A2572} 2052:{0F6AAF5B-3089-4837-AC63-DEEC282862D9} 2057:{F3CAA239-F0FC-456F-B3F8-D5D846030731} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{482E9390-1005-42FD-9F3F-E160E0E6FB19} 1049:{8FE09AC2-814B-42FC-9FCE-53D45A396529} 2052:{4FABD326-8345-438B-82B8-66C2DC3676E6} 2057:{7ECFFF43-DEC7-4B7F-BC88-260A10AF132A} " Type="16"/>
     <ROW Property="ProductLanguage" Value="2057"/>
     <ROW Property="ProductName" Value="Qortal"/>
-    <ROW Property="ProductVersion" Value="1.5.2" Type="32"/>
+    <ROW Property="ProductVersion" Value="1.6.0" 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="{922F3242-D791-484E-B034-2EC3EBE7E57F}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
+    <ROW Component="AI_CustomARPName" ComponentId="{7941AD6C-7C09-48E7-93ED-0340E0F52EC0}" 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"/>

WindowsInstaller/README.md

@@ -12,7 +12,7 @@ configured paths, or create a dummy `D:` drive with the expected layout.
 
 Typical build procedure:
 
-* Overwrite the `qortal.jar` file in `Install-Files\`
+* Place the `qortal.jar` file in `Install-Files\`
 * Open AdvancedInstaller with qortal.aip file
 * If releasing a new version, change version number in:
 	+ "Product Information" side menu

pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>1.5.3</version>
+	<version>1.7.0</version>
 	<packaging>jar</packaging>
 	<properties>
 		<skipTests>true</skipTests>

src/main/java/org/qortal/api/ApiError.java

@@ -129,7 +129,10 @@ public enum ApiError {
 	// Foreign blockchain
 	FOREIGN_BLOCKCHAIN_NETWORK_ISSUE(1201, 500),
 	FOREIGN_BLOCKCHAIN_BALANCE_ISSUE(1202, 402),
-	FOREIGN_BLOCKCHAIN_TOO_SOON(1203, 408);
+	FOREIGN_BLOCKCHAIN_TOO_SOON(1203, 408),
+
+	// Trade portal
+	ORDER_SIZE_TOO_SMALL(1300, 402);
 
 	private static final Map<Integer, ApiError> map = stream(ApiError.values()).collect(toMap(apiError -> apiError.code, apiError -> apiError));
 
@@ -157,4 +160,4 @@ public enum ApiError {
 		return this.status;
 	}
 
-}
+}

src/main/java/org/qortal/api/ApiService.java

@@ -14,6 +14,8 @@ import java.security.SecureRandom;
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RedirectPatternRule;
 import org.eclipse.jetty.rewrite.handler.RewriteHandler;
@@ -50,6 +52,8 @@ import org.qortal.settings.Settings;
 
 public class ApiService {
 
+	private static final Logger LOGGER = LogManager.getLogger(ApiService.class);
+
 	private static ApiService instance;
 
 	private final ResourceConfig config;
@@ -203,6 +207,9 @@ public class ApiService {
 			context.addServlet(TradeBotWebSocket.class, "/websockets/crosschain/tradebot");
 			context.addServlet(PresenceWebSocket.class, "/websockets/presence");
 
+			// Warn about API security if needed
+			this.checkApiSecurity();
+
 			// Start server
 			this.server.start();
 		} catch (Exception e) {
@@ -222,4 +229,23 @@ public class ApiService {
 		this.server = null;
 	}
 
+	private void checkApiSecurity() {
+		// Warn about API security if needed
+		boolean allConnectionsAllowed = false;
+		if (Settings.getInstance().isApiKeyDisabled()) {
+			for (String pattern : Settings.getInstance().getApiWhitelist()) {
+				if (pattern.startsWith("0.0.0.0/") || pattern.startsWith("::/") || pattern.endsWith("/0")) {
+					allConnectionsAllowed = true;
+				}
+			}
+
+			if (allConnectionsAllowed) {
+				LOGGER.warn("Warning: API key validation is currently disabled, and the API whitelist " +
+						"is allowing all connections. This can be a security risk.");
+				LOGGER.warn("To fix, set the apiKeyDisabled setting to false, or allow only specific local " +
+						"IP addresses using the apiWhitelist setting.");
+			}
+		}
+	}
+
 }

src/main/java/org/qortal/api/Security.java

@@ -12,6 +12,11 @@ public abstract class Security {
 	public static final String API_KEY_HEADER = "X-API-KEY";
 
 	public static void checkApiCallAllowed(HttpServletRequest request) {
+		// If API key checking has been disabled, we will allow the request in all cases
+		boolean isApiKeyDisabled = Settings.getInstance().isApiKeyDisabled();
+		if (isApiKeyDisabled)
+			return;
+
 		String expectedApiKey = Settings.getInstance().getApiKey();
 		String passedApiKey = request.getHeader(API_KEY_HEADER);
 

src/main/java/org/qortal/api/model/AddressListRequest.java

@@ -0,0 +1,18 @@
+package org.qortal.api.model;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import java.util.List;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class AddressListRequest {
+
+	@Schema(description = "A list of addresses")
+	public List<String> addresses;
+
+	public AddressListRequest() {
+	}
+
+}

src/main/java/org/qortal/api/model/CrossChainTradeSummary.java

@@ -25,6 +25,12 @@ public class CrossChainTradeSummary {
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private long foreignAmount;
 
+	private String atAddress;
+
+	private String sellerAddress;
+
+	private String buyerReceivingAddress;
+
 	protected CrossChainTradeSummary() {
 		/* For JAXB */
 	}
@@ -34,6 +40,9 @@ public class CrossChainTradeSummary {
 		this.qortAmount = crossChainTradeData.qortAmount;
 		this.foreignAmount = crossChainTradeData.expectedForeignAmount;
 		this.btcAmount = this.foreignAmount;
+		this.sellerAddress = crossChainTradeData.qortalCreator;
+		this.buyerReceivingAddress = crossChainTradeData.qortalPartnerReceivingAddress;
+		this.atAddress = crossChainTradeData.qortalAtAddress;
 	}
 
 	public long getTradeTimestamp() {
@@ -48,7 +57,11 @@ public class CrossChainTradeSummary {
 		return this.btcAmount;
 	}
 
-	public long getForeignAmount() {
-		return this.foreignAmount;
-	}
+	public long getForeignAmount() { return this.foreignAmount; }
+
+	public String getAtAddress() { return this.atAddress; }
+
+	public String getSellerAddress() { return this.sellerAddress; }
+
+	public String getBuyerReceivingAddressAddress() { return this.buyerReceivingAddress; }
 }

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

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

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

@@ -553,13 +553,13 @@ public class AdminResource {
 	@Path("/repository/data")
 	@Operation(
 		summary = "Import data into repository.",
-		description = "Imports data from file on local machine. Filename is forced to 'import.json' if apiKey is not set.",
+		description = "Imports data from file on local machine. Filename is forced to 'qortal-backup/TradeBotStates.json' if apiKey is not set.",
 		requestBody = @RequestBody(
 			required = true,
 			content = @Content(
 				mediaType = MediaType.TEXT_PLAIN,
 				schema = @Schema(
-					type = "string", example = "MintingAccounts.script"
+					type = "string", example = "qortal-backup/TradeBotStates.json"
 				)
 			)
 		),
@@ -577,7 +577,7 @@ public class AdminResource {
 
 		// Hard-coded because it's too dangerous to allow user-supplied filenames in weaker security contexts
 		if (Settings.getInstance().getApiKey() == null)
-			filename = "import.json";
+			filename = "qortal-backup/TradeBotStates.json";
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();

src/main/java/org/qortal/api/resource/CrossChainDogecoinACCTv1Resource.java

@@ -0,0 +1,140 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+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.tags.Tag;
+import org.qortal.account.PrivateKeyAccount;
+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.CrossChainSecretRequest;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crosschain.DogecoinACCTv1;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.Transformer;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import java.util.Arrays;
+
+@Path("/crosschain/DogecoinACCTv1")
+@Tag(name = "Cross-Chain (DogecoinACCTv1)")
+public class CrossChainDogecoinACCTv1Resource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/redeemmessage")
+	@Operation(
+		summary = "Signs and broadcasts a 'redeem' MESSAGE transaction that sends secrets to AT, releasing funds to partner",
+		description = "Specify address of cross-chain AT that needs to be messaged, Alice's trade private key, the 32-byte secret,<br>"
+			+ "and an address for receiving QORT from AT. All of these can be found in Alice's trade bot data.<br>"
+			+ "AT needs to be in 'trade' mode. Messages sent to an AT in any other mode will be ignored, but still cost fees to send!<br>"
+			+ "You need to use the private key that the AT considers the trade 'partner' otherwise the MESSAGE transaction will be invalid.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = CrossChainSecretRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_DATA, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public boolean buildRedeemMessage(CrossChainSecretRequest secretRequest) {
+		Security.checkApiCallAllowed(request);
+
+		byte[] partnerPrivateKey = secretRequest.partnerPrivateKey;
+
+		if (partnerPrivateKey == null || partnerPrivateKey.length != Transformer.PRIVATE_KEY_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		if (secretRequest.atAddress == null || !Crypto.isValidAtAddress(secretRequest.atAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (secretRequest.secret == null || secretRequest.secret.length != DogecoinACCTv1.SECRET_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (secretRequest.receivingAddress == null || !Crypto.isValidAddress(secretRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = fetchAtDataWithChecking(repository, secretRequest.atAddress);
+			CrossChainTradeData crossChainTradeData = DogecoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+			if (crossChainTradeData.mode != AcctMode.TRADING)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			byte[] partnerPublicKey = new PrivateKeyAccount(null, partnerPrivateKey).getPublicKey();
+			String partnerAddress = Crypto.toAddress(partnerPublicKey);
+
+			// MESSAGE must come from address that AT considers trade partner
+			if (!crossChainTradeData.qortalPartnerAddress.equals(partnerAddress))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+			// Good to make MESSAGE
+
+			byte[] messageData = DogecoinACCTv1.buildRedeemMessage(secretRequest.secret, secretRequest.receivingAddress);
+
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, partnerPrivateKey);
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, secretRequest.atAddress, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_INVALID);
+
+			return true;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	private ATData fetchAtDataWithChecking(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		if (atData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+		// Must be correct AT - check functionality using code hash
+		if (!Arrays.equals(atData.getCodeHash(), DogecoinACCTv1.CODE_BYTES_HASH))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// No point sending message to AT that's finished
+		if (atData.getIsFinished())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		return atData;
+	}
+
+}

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

@@ -0,0 +1,165 @@
+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.tags.Tag;
+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.DogecoinSendRequest;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Dogecoin;
+import org.qortal.crosschain.SimpleTransaction;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import java.util.List;
+
+@Path("/crosschain/doge")
+@Tag(name = "Cross-Chain (Dogecoin)")
+public class CrossChainDogecoinResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/walletbalance")
+	@Operation(
+		summary = "Returns DOGE 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})
+	public String getDogecoinWalletBalance(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		if (!dogecoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Long balance = dogecoin.getWalletBalance(key58);
+		if (balance == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+		return balance.toString();
+	}
+
+	@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})
+	public List<SimpleTransaction> getDogecoinWalletTransactions(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		if (!dogecoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return dogecoin.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/send")
+	@Operation(
+		summary = "Sends DOGE from hierarchical, deterministic BIP32 wallet to specific address",
+		description = "Currently only supports 'legacy' P2PKH Dogecoin 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 = DogecoinSendRequest.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})
+	public String sendBitcoin(DogecoinSendRequest dogecoinSendRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (dogecoinSendRequest.dogecoinAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (dogecoinSendRequest.feePerByte != null && dogecoinSendRequest.feePerByte <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		if (!dogecoin.isValidAddress(dogecoinSendRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (!dogecoin.isValidDeterministicKey(dogecoinSendRequest.xprv58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Transaction spendTransaction = dogecoin.buildSpend(dogecoinSendRequest.xprv58,
+				dogecoinSendRequest.receivingAddress,
+				dogecoinSendRequest.dogecoinAmount,
+				dogecoinSendRequest.feePerByte);
+
+		if (spendTransaction == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+		try {
+			dogecoin.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/CrossChainHtlcResource.java

@@ -11,6 +11,7 @@ import java.util.List;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.GET;
+import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.core.Context;
@@ -46,7 +47,7 @@ public class CrossChainHtlcResource {
 	@Path("/address/{blockchain}/{refundPKH}/{locktime}/{redeemPKH}/{hashOfSecret}")
 	@Operation(
 		summary = "Returns HTLC address based on trade info",
-		description = "Blockchain can be BITCOIN or LITECOIN. Public key hashes (PKH) and hash of secret should be 20 bytes (base58 encoded). Locktime is seconds since epoch.",
+		description = "Public key hashes (PKH) and hash of secret should be 20 bytes (base58 encoded). Locktime is seconds since epoch.",
 		responses = {
 			@ApiResponse(
 				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
@@ -96,7 +97,7 @@ public class CrossChainHtlcResource {
 	@Path("/status/{blockchain}/{refundPKH}/{locktime}/{redeemPKH}/{hashOfSecret}")
 	@Operation(
 		summary = "Checks HTLC status",
-		description = "Blockchain can be BITCOIN or LITECOIN. Public key hashes (PKH) and hash of secret should be 20 bytes (base58 encoded). Locktime is seconds since epoch.",
+		description = "Public key hashes (PKH) and hash of secret should be 20 bytes (base58 encoded). Locktime is seconds since epoch.",
 		responses = {
 			@ApiResponse(
 				content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = CrossChainBitcoinyHTLCStatus.class))
@@ -173,56 +174,11 @@ public class CrossChainHtlcResource {
 		}
 	}
 
-	@GET
-	@Path("/redeem/LITECOIN/{ataddress}/{tradePrivateKey}/{secret}/{receivingAddress}")
-	@Operation(
-			summary = "Redeems HTLC associated with supplied AT, using private key, secret, and receiving address",
-			description = "Secret and private key should be 32 bytes (base58 encoded). Receiving address must be a valid LTC P2PKH address.<br>" +
-					"The secret can be found in Alice's trade bot data or in the message to Bob's AT.<br>" +
-					"The trade private key and receiving address can be found in Bob's trade bot data.",
-			responses = {
-					@ApiResponse(
-							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
-					)
-			}
-	)
-	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN})
-	public boolean redeemHtlc(@PathParam("ataddress") String atAddress,
-							  @PathParam("tradePrivateKey") String tradePrivateKey,
-							  @PathParam("secret") String secret,
-							  @PathParam("receivingAddress") String receivingAddress) {
-		Security.checkApiCallAllowed(request);
-
-		// base58 decode the trade private key
-		byte[] decodedTradePrivateKey = null;
-		if (tradePrivateKey != null)
-			decodedTradePrivateKey = Base58.decode(tradePrivateKey);
-
-		// base58 decode the secret
-		byte[] decodedSecret = null;
-		if (secret != null)
-			decodedSecret = Base58.decode(secret);
-
-		// Convert supplied Litecoin receiving address into public key hash (we only support P2PKH at this time)
-		Address litecoinReceivingAddress;
-		try {
-			litecoinReceivingAddress = Address.fromString(Litecoin.getInstance().getNetworkParameters(), receivingAddress);
-		} catch (AddressFormatException e) {
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
-		}
-		if (litecoinReceivingAddress.getOutputScriptType() != Script.ScriptType.P2PKH)
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
-
-		byte[] litecoinReceivingAccountInfo = litecoinReceivingAddress.getHash();
-
-		return this.doRedeemHtlc(atAddress, decodedTradePrivateKey, decodedSecret, litecoinReceivingAccountInfo);
-	}
-
-	@GET
-	@Path("/redeem/LITECOIN/{ataddress}")
+	@POST
+	@Path("/redeem/{ataddress}")
 	@Operation(
 			summary = "Redeems HTLC associated with supplied AT",
-			description = "To be used by a QORT seller (Bob) who needs to redeem LTC proceeds that are stuck in a P2SH.<br>" +
+			description = "To be used by a QORT seller (Bob) who needs to redeem LTC/DOGE/etc proceeds that are stuck in a P2SH.<br>" +
 					"This requires Bob's trade bot data to be present in the database for this AT.<br>" +
 					"It will fail if the buyer has yet to redeem the QORT held in the AT.",
 			responses = {
@@ -249,7 +205,7 @@ public class CrossChainHtlcResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
 			// Attempt to find secret from the buyer's message to AT
-			byte[] decodedSecret = LitecoinACCTv1.findSecretA(repository, crossChainTradeData);
+			byte[] decodedSecret = acct.findSecretA(repository, crossChainTradeData);
 			if (decodedSecret == null) {
 				LOGGER.info(() -> String.format("Unable to find secret-A from redeem message to AT %s", atAddress));
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
@@ -263,24 +219,24 @@ public class CrossChainHtlcResource {
 			if (tradeBotData != null)
 				decodedPrivateKey = tradeBotData.getTradePrivateKey();
 
-			// Search for the litecoin receiving address in the tradebot data
-			byte[] litecoinReceivingAccountInfo = null;
+			// Search for the foreign blockchain receiving address in the tradebot data
+			byte[] foreignBlockchainReceivingAccountInfo = null;
 			if (tradeBotData != null)
 				// Use receiving address PKH from tradebot data
-				litecoinReceivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+				foreignBlockchainReceivingAccountInfo = tradeBotData.getReceivingAccountInfo();
 
-			return this.doRedeemHtlc(atAddress, decodedPrivateKey, decodedSecret, litecoinReceivingAccountInfo);
+			return this.doRedeemHtlc(atAddress, decodedPrivateKey, decodedSecret, foreignBlockchainReceivingAccountInfo);
 
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
 	}
 
-	@GET
-	@Path("/redeemAll/LITECOIN")
+	@POST
+	@Path("/redeemAll")
 	@Operation(
 			summary = "Redeems HTLC for all applicable ATs in tradebot data",
-			description = "To be used by a QORT seller (Bob) who needs to redeem LTC proceeds that are stuck in P2SH transactions.<br>" +
+			description = "To be used by a QORT seller (Bob) who needs to redeem LTC/DOGE/etc proceeds that are stuck in P2SH transactions.<br>" +
 					"This requires Bob's trade bot data to be present in the database for any ATs that need redeeming.<br>" +
 					"Returns true if at least one trade is redeemed. More detail is available in the log.txt.* file.",
 			responses = {
@@ -333,7 +289,7 @@ public class CrossChainHtlcResource {
 				}
 
 				// Attempt to find secret from the buyer's message to AT
-				byte[] decodedSecret = LitecoinACCTv1.findSecretA(repository, crossChainTradeData);
+				byte[] decodedSecret = acct.findSecretA(repository, crossChainTradeData);
 				if (decodedSecret == null) {
 					LOGGER.info("Unable to find secret-A from redeem message to AT {}", atAddress);
 					continue;
@@ -342,12 +298,12 @@ public class CrossChainHtlcResource {
 				// Search for the tradePrivateKey in the tradebot data
 				byte[] decodedPrivateKey = tradeBotData.getTradePrivateKey();
 
-				// Search for the litecoin receiving address PKH in the tradebot data
-				byte[] litecoinReceivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+				// Search for the foreign blockchain receiving address PKH in the tradebot data
+				byte[] foreignBlockchainReceivingAccountInfo = tradeBotData.getReceivingAccountInfo();
 
 				try {
 					LOGGER.info("Attempting to redeem P2SH balance associated with AT {}...", atAddress);
-					boolean redeemed = this.doRedeemHtlc(atAddress, decodedPrivateKey, decodedSecret, litecoinReceivingAccountInfo);
+					boolean redeemed = this.doRedeemHtlc(atAddress, decodedPrivateKey, decodedSecret, foreignBlockchainReceivingAccountInfo);
 					if (redeemed) {
 						LOGGER.info("Redeemed P2SH balance associated with AT {}", atAddress);
 						success = true;
@@ -367,8 +323,10 @@ public class CrossChainHtlcResource {
 		return success;
 	}
 
-	private boolean doRedeemHtlc(String atAddress, byte[] decodedTradePrivateKey, byte[] decodedSecret, byte[] litecoinReceivingAccountInfo) {
+	private boolean doRedeemHtlc(String atAddress, byte[] decodedTradePrivateKey, byte[] decodedSecret,
+								 byte[] foreignBlockchainReceivingAccountInfo) {
 		try (final Repository repository = RepositoryManager.getRepository()) {
+
 			ATData atData = repository.getATRepository().fromATAddress(atAddress);
 			if (atData == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
@@ -390,30 +348,34 @@ public class CrossChainHtlcResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
 			// Validate receiving address
-			if (litecoinReceivingAccountInfo == null || litecoinReceivingAccountInfo.length != 20)
+			if (foreignBlockchainReceivingAccountInfo == null || foreignBlockchainReceivingAccountInfo.length != 20)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
-			// Make sure the receiving address isn't a QORT address, given that we can share the same field for both QORT and LTC
-			if (Crypto.isValidAddress(litecoinReceivingAccountInfo))
-				if (Base58.encode(litecoinReceivingAccountInfo).startsWith("Q"))
-					// This is likely a QORT address, not an LTC
+			// Make sure the receiving address isn't a QORT address, given that we can share the same field for both QORT and foreign blockchains
+			if (Crypto.isValidAddress(foreignBlockchainReceivingAccountInfo))
+				if (Base58.encode(foreignBlockchainReceivingAccountInfo).startsWith("Q"))
+					// This is likely a QORT address, not a foreign blockchain
 					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
 
 			// Use secret-A to redeem P2SH-A
 
-			Litecoin litecoin = Litecoin.getInstance();
+			Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
+			if (bitcoiny.getClass() == Bitcoin.class) {
+				LOGGER.info("Redeeming a Bitcoin HTLC is not yet supported");
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+			}
 
 			int lockTime = crossChainTradeData.lockTimeA;
 			byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTime, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
-			String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+			String p2shAddressA = bitcoiny.deriveP2shAddress(redeemScriptA);
 			LOGGER.info(String.format("Redeeming P2SH address: %s", p2shAddressA));
 
 			// Fee for redeem/refund is subtracted from P2SH-A balance.
 			long feeTimestamp = calcFeeTimestamp(lockTime, crossChainTradeData.tradeTimeout);
-			long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+			long p2shFee = bitcoiny.getP2shFee(feeTimestamp);
 			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
-			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
 
 			switch (htlcStatusA) {
 				case UNFUNDED:
@@ -434,13 +396,14 @@ public class CrossChainHtlcResource {
 				case FUNDED: {
 					Coin redeemAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
 					ECKey redeemKey = ECKey.fromPrivate(decodedTradePrivateKey);
-					List<TransactionOutput> fundingOutputs = litecoin.getUnspentOutputs(p2shAddressA);
+					List<TransactionOutput> fundingOutputs = bitcoiny.getUnspentOutputs(p2shAddressA);
 
-					Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(litecoin.getNetworkParameters(), redeemAmount, redeemKey,
-							fundingOutputs, redeemScriptA, decodedSecret, litecoinReceivingAccountInfo);
+					Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(bitcoiny.getNetworkParameters(), redeemAmount, redeemKey,
+							fundingOutputs, redeemScriptA, decodedSecret, foreignBlockchainReceivingAccountInfo);
 
-					litecoin.broadcastTransaction(p2shRedeemTransaction);
-					return true; // TODO: validate?
+					bitcoiny.broadcastTransaction(p2shRedeemTransaction);
+					LOGGER.info(String.format("P2SH address %s redeemed!", p2shAddressA));
+					return true;
 				}
 			}
 
@@ -453,11 +416,11 @@ public class CrossChainHtlcResource {
 		return false;
 	}
 
-	@GET
-	@Path("/refund/LITECOIN/{ataddress}")
+	@POST
+	@Path("/refund/{ataddress}")
 	@Operation(
 			summary = "Refunds HTLC associated with supplied AT",
-			description = "To be used by a QORT buyer (Alice) who needs to refund their LTC that is stuck in a P2SH.<br>" +
+			description = "To be used by a QORT buyer (Alice) who needs to refund their LTC/DOGE/etc that is stuck in a P2SH.<br>" +
 					"This requires Alice's trade bot data to be present in the database for this AT.<br>" +
 					"It will fail if it's already redeemed by the seller, or if the lockTime (60 minutes) hasn't passed yet.",
 			responses = {
@@ -479,9 +442,17 @@ public class CrossChainHtlcResource {
 			if (tradeBotData.getForeignKey() == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
-			// Determine LTC receive address for refund
-			Litecoin litecoin = Litecoin.getInstance();
-			String receiveAddress = litecoin.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			if (atData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+			ACCT acct = SupportedBlockchain.getAcctByCodeHash(atData.getCodeHash());
+			if (acct == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			// Determine foreign blockchain receive address for refund
+			Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
+			String receiveAddress = bitcoiny.getUnusedReceiveAddress(tradeBotData.getForeignKey());
 
 			return this.doRefundHtlc(atAddress, receiveAddress);
 
@@ -492,11 +463,12 @@ public class CrossChainHtlcResource {
 		}
 	}
 
-	@GET
-	@Path("/refund/LITECOIN/{ataddress}/{receivingAddress}")
+
+	@POST
+	@Path("/refundAll")
 	@Operation(
-			summary = "Refunds HTLC associated with supplied AT, to the specified LTC receiving address",
-			description = "To be used by a QORT buyer (Alice) who needs to refund their LTC that is stuck in a P2SH.<br>" +
+			summary = "Refunds HTLC for all applicable ATs in tradebot data",
+			description = "To be used by a QORT buyer (Alice) who needs to refund their LTC/DOGE/etc proceeds that are stuck in P2SH transactions.<br>" +
 					"This requires Alice's trade bot data to be present in the database for this AT.<br>" +
 					"It will fail if it's already redeemed by the seller, or if the lockTime (60 minutes) hasn't passed yet.",
 			responses = {
@@ -506,15 +478,83 @@ public class CrossChainHtlcResource {
 			}
 	)
 	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN})
-	public boolean refundHtlc(@PathParam("ataddress") String atAddress,
-							  @PathParam("receivingAddress") String receivingAddress) {
+	public boolean refundAllHtlc() {
 		Security.checkApiCallAllowed(request);
-		return this.doRefundHtlc(atAddress, receivingAddress);
+		boolean success = false;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<TradeBotData> allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
+
+			for (TradeBotData tradeBotData : allTradeBotData) {
+				String atAddress = tradeBotData.getAtAddress();
+				if (atAddress == null) {
+					LOGGER.info("Missing AT address in tradebot data", atAddress);
+					continue;
+				}
+
+				String tradeState = tradeBotData.getState();
+				if (tradeState == null) {
+					LOGGER.info("Missing trade state for AT {}", atAddress);
+					continue;
+				}
+
+				if (tradeState.startsWith("BOB")) {
+					LOGGER.info("AT {} isn't refundable because it is a sell order", atAddress);
+					continue;
+				}
+
+				ATData atData = repository.getATRepository().fromATAddress(atAddress);
+				if (atData == null) {
+					LOGGER.info("Couldn't find AT with address {}", atAddress);
+					continue;
+				}
+
+				ACCT acct = SupportedBlockchain.getAcctByCodeHash(atData.getCodeHash());
+				if (acct == null) {
+					continue;
+				}
+
+				CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atData);
+				if (crossChainTradeData == null) {
+					LOGGER.info("Couldn't find crosschain trade data for AT {}", atAddress);
+					continue;
+				}
+
+				if (tradeBotData.getForeignKey() == null) {
+					LOGGER.info("Couldn't find foreign key for AT {}", atAddress);
+					continue;
+				}
+
+				try {
+					// Determine foreign blockchain receive address for refund
+					Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
+					String receivingAddress = bitcoiny.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+
+					LOGGER.info("Attempting to refund P2SH balance associated with AT {}...", atAddress);
+					boolean refunded = this.doRefundHtlc(atAddress, receivingAddress);
+					if (refunded) {
+						LOGGER.info("Refunded P2SH balance associated with AT {}", atAddress);
+						success = true;
+					}
+					else {
+						LOGGER.info("Couldn't refund P2SH balance associated with AT {}. Already redeemed?", atAddress);
+					}
+				} catch (ApiException | ForeignBlockchainException e) {
+					LOGGER.info("Couldn't refund P2SH balance associated with AT {}. Missing data?", atAddress);
+				}
+			}
+
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+
+		return success;
 	}
 
 
 	private boolean doRefundHtlc(String atAddress, String receiveAddress) {
 		try (final Repository repository = RepositoryManager.getRepository()) {
+
 			ATData atData = repository.getATRepository().fromATAddress(atAddress);
 			if (atData == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
@@ -527,11 +567,23 @@ public class CrossChainHtlcResource {
 			if (crossChainTradeData == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
+			// If the AT is "finished" then it will have a zero balance
+			// In these cases we should avoid HTLC refunds if tbe QORT haven't been returned to the seller
+			if (atData.getIsFinished() && crossChainTradeData.mode != AcctMode.REFUNDED && crossChainTradeData.mode != AcctMode.CANCELLED) {
+				LOGGER.info(String.format("Skipping AT %s because the QORT has already been redemed", atAddress));
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+			}
+
 			List<TradeBotData> allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
 			TradeBotData tradeBotData = allTradeBotData.stream().filter(tradeBotDataItem -> tradeBotDataItem.getAtAddress().equals(atAddress)).findFirst().orElse(null);
 			if (tradeBotData == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
+			Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
+			if (bitcoiny.getClass() == Bitcoin.class) {
+				LOGGER.info("Refunding a Bitcoin HTLC is not yet supported");
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+			}
 
 			int lockTime = tradeBotData.getLockTimeA();
 
@@ -539,22 +591,20 @@ public class CrossChainHtlcResource {
 			if (NTP.getTime() <= lockTime * 1000L)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON);
 
-			Litecoin litecoin = Litecoin.getInstance();
-
 			// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
-			int medianBlockTime = litecoin.getMedianBlockTime();
+			int medianBlockTime = bitcoiny.getMedianBlockTime();
 			if (medianBlockTime <= lockTime)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON);
 
 			byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
-			String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+			String p2shAddressA = bitcoiny.deriveP2shAddress(redeemScriptA);
 			LOGGER.info(String.format("Refunding P2SH address: %s", p2shAddressA));
 
 			// Fee for redeem/refund is subtracted from P2SH-A balance.
 			long feeTimestamp = calcFeeTimestamp(lockTime, crossChainTradeData.tradeTimeout);
-			long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+			long p2shFee = bitcoiny.getP2shFee(feeTimestamp);
 			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
-			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
 
 			switch (htlcStatusA) {
 				case UNFUNDED:
@@ -572,18 +622,18 @@ public class CrossChainHtlcResource {
 				case FUNDED:{
 					Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
 					ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
-					List<TransactionOutput> fundingOutputs = litecoin.getUnspentOutputs(p2shAddressA);
+					List<TransactionOutput> fundingOutputs = bitcoiny.getUnspentOutputs(p2shAddressA);
 
-					// Validate the destination LTC address
-					Address receiving = Address.fromString(litecoin.getNetworkParameters(), receiveAddress);
+					// Validate the destination foreign blockchain address
+					Address receiving = Address.fromString(bitcoiny.getNetworkParameters(), receiveAddress);
 					if (receiving.getOutputScriptType() != Script.ScriptType.P2PKH)
 						throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
-					Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(litecoin.getNetworkParameters(), refundAmount, refundKey,
+					Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(bitcoiny.getNetworkParameters(), refundAmount, refundKey,
 							fundingOutputs, redeemScriptA, lockTime, receiving.getHash());
 
-					litecoin.broadcastTransaction(p2shRefundTransaction);
-					return true; // TODO: validate?
+					bitcoiny.broadcastTransaction(p2shRefundTransaction);
+					return true;
 				}
 			}
 

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

@@ -107,7 +107,7 @@ public class CrossChainTradeBotResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.INSUFFICIENT_BALANCE, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.INSUFFICIENT_BALANCE, ApiError.REPOSITORY_ISSUE, ApiError.ORDER_SIZE_TOO_SMALL})
 	@SuppressWarnings("deprecation")
 	public String tradeBotCreator(TradeBotCreateRequest tradeBotCreateRequest) {
 		Security.checkApiCallAllowed(request);
@@ -128,10 +128,13 @@ public class CrossChainTradeBotResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
 		if (tradeBotCreateRequest.foreignAmount == null || tradeBotCreateRequest.foreignAmount <= 0)
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ORDER_SIZE_TOO_SMALL);
+
+		if (tradeBotCreateRequest.foreignAmount < foreignBlockchain.getMinimumOrderAmount())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ORDER_SIZE_TOO_SMALL);
 
 		if (tradeBotCreateRequest.qortAmount <= 0 || tradeBotCreateRequest.fundingQortAmount <= 0)
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ORDER_SIZE_TOO_SMALL);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			// Do some simple checking first
@@ -283,4 +286,4 @@ public class CrossChainTradeBotResource {
 		return atData;
 	}
 
-}
+}

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

@@ -0,0 +1,298 @@
+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.tags.Tag;
+
+import org.qortal.api.*;
+import org.qortal.api.model.AddressListRequest;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.account.AccountData;
+import org.qortal.list.ResourceListManager;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.*;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+
+@Path("/lists")
+@Tag(name = "Lists")
+public class ListsResource {
+
+	@Context
+	HttpServletRequest request;
+	
+	@POST
+	@Path("/blacklist/address/{address}")
+	@Operation(
+		summary = "Add a QORT address to the local blacklist",
+		responses = {
+			@ApiResponse(
+				description = "Returns true on success, or an exception on failure",
+					content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String addAddressToBlacklist(@PathParam("address") String address) {
+		Security.checkApiCallAllowed(request);
+
+		if (!Crypto.isValidAddress(address))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+			// Not found?
+			if (accountData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+			// Valid address, so go ahead and blacklist it
+			boolean success = ResourceListManager.getInstance().addAddressToBlacklist(address, true);
+
+			return success ? "true" : "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/blacklist/addresses")
+	@Operation(
+			summary = "Add one or more QORT addresses to the local blacklist",
+			requestBody = @RequestBody(
+					required = true,
+					content = @Content(
+							mediaType = MediaType.APPLICATION_JSON,
+							schema = @Schema(
+									implementation = AddressListRequest.class
+							)
+					)
+			),
+			responses = {
+					@ApiResponse(
+							description = "Returns true if all addresses were processed, false if any couldn't be " +
+									"processed, or an exception on failure. If false or an exception is returned, " +
+									"the list will not be updated, and the request will need to be re-issued.",
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
+					)
+			}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String addAddressesToBlacklist(AddressListRequest addressListRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (addressListRequest == null || addressListRequest.addresses == null) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		}
+
+		int successCount = 0;
+		int errorCount = 0;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+
+			for (String address : addressListRequest.addresses) {
+
+				if (!Crypto.isValidAddress(address)) {
+					errorCount++;
+					continue;
+				}
+
+				AccountData accountData = repository.getAccountRepository().getAccount(address);
+				// Not found?
+				if (accountData == null) {
+					errorCount++;
+					continue;
+				}
+
+				// Valid address, so go ahead and blacklist it
+				boolean success = ResourceListManager.getInstance().addAddressToBlacklist(address, false);
+				if (success) {
+					successCount++;
+				}
+				else {
+					errorCount++;
+				}
+			}
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+
+		if (successCount > 0 && errorCount == 0) {
+			// All were successful, so save the blacklist
+			ResourceListManager.getInstance().saveBlacklist();
+			return "true";
+		}
+		else {
+			// Something went wrong, so revert
+			ResourceListManager.getInstance().revertBlacklist();
+			return "false";
+		}
+	}
+
+
+	@DELETE
+	@Path("/blacklist/address/{address}")
+	@Operation(
+			summary = "Remove a QORT address from the local blacklist",
+			responses = {
+					@ApiResponse(
+							description = "Returns true on success, or an exception on failure",
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
+					)
+			}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String removeAddressFromBlacklist(@PathParam("address") String address) {
+		Security.checkApiCallAllowed(request);
+
+		if (!Crypto.isValidAddress(address))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+			// Not found?
+			if (accountData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+			// Valid address, so go ahead and blacklist it
+			boolean success = ResourceListManager.getInstance().removeAddressFromBlacklist(address, true);
+
+			return success ? "true" : "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@DELETE
+	@Path("/blacklist/addresses")
+	@Operation(
+			summary = "Remove one or more QORT addresses from the local blacklist",
+			requestBody = @RequestBody(
+					required = true,
+					content = @Content(
+							mediaType = MediaType.APPLICATION_JSON,
+							schema = @Schema(
+									implementation = AddressListRequest.class
+							)
+					)
+			),
+			responses = {
+					@ApiResponse(
+							description = "Returns true if all addresses were processed, false if any couldn't be " +
+									"processed, or an exception on failure. If false or an exception is returned, " +
+									"the list will not be updated, and the request will need to be re-issued.",
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
+					)
+			}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String removeAddressesFromBlacklist(AddressListRequest addressListRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (addressListRequest == null || addressListRequest.addresses == null) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		}
+
+		int successCount = 0;
+		int errorCount = 0;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+
+			for (String address : addressListRequest.addresses) {
+
+				if (!Crypto.isValidAddress(address)) {
+					errorCount++;
+					continue;
+				}
+
+				AccountData accountData = repository.getAccountRepository().getAccount(address);
+				// Not found?
+				if (accountData == null) {
+					errorCount++;
+					continue;
+				}
+
+				// Valid address, so go ahead and blacklist it
+				// Don't save as we will do this at the end of the process
+				boolean success = ResourceListManager.getInstance().removeAddressFromBlacklist(address, false);
+				if (success) {
+					successCount++;
+				}
+				else {
+					errorCount++;
+				}
+			}
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+
+		if (successCount > 0 && errorCount == 0) {
+			// All were successful, so save the blacklist
+			ResourceListManager.getInstance().saveBlacklist();
+			return "true";
+		}
+		else {
+			// Something went wrong, so revert
+			ResourceListManager.getInstance().revertBlacklist();
+			return "false";
+		}
+	}
+
+	@GET
+	@Path("/blacklist/addresses")
+	@Operation(
+			summary = "Fetch the list of blacklisted addresses",
+			responses = {
+					@ApiResponse(
+							description = "A JSON array of addresses",
+							content = @Content(mediaType = MediaType.APPLICATION_JSON, array = @ArraySchema(schema = @Schema(implementation = String.class)))
+					)
+			}
+	)
+	public String getAddressBlacklist() {
+		Security.checkApiCallAllowed(request);
+		return ResourceListManager.getInstance().getBlacklistJSONString();
+	}
+
+	@GET
+	@Path("/blacklist/address/{address}")
+	@Operation(
+			summary = "Check if an address is present in the local blacklist",
+			responses = {
+					@ApiResponse(
+							description = "Returns true or false if the list was queried, or an exception on failure",
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean"))
+					)
+			}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String checkAddressInBlacklist(@PathParam("address") String address) {
+		Security.checkApiCallAllowed(request);
+
+		if (!Crypto.isValidAddress(address))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+			// Not found?
+			if (accountData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+			// Valid address, so go ahead and blacklist it
+			boolean blacklisted = ResourceListManager.getInstance().isAddressInBlacklist(address);
+
+			return blacklisted ? "true" : "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+}

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

@@ -33,7 +33,6 @@ import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.transform.transaction.TransactionTransformer.Transformation;
-import org.qortal.utils.BIP39;
 import org.qortal.utils.Base58;
 
 import com.google.common.hash.HashCode;
@@ -195,123 +194,6 @@ public class UtilsResource {
 		return Base58.encode(random);
 	}
 
-	@GET
-	@Path("/mnemonic")
-	@Operation(
-		summary = "Generate 12-word BIP39 mnemonic",
-		description = "Optionally pass 16-byte, base58-encoded entropy or entropy will be internally generated.<br>"
-				+ "Example entropy input: YcVfxkQb6JRzqk5kF2tNLv",
-		responses = {
-			@ApiResponse(
-				description = "mnemonic",
-				content = @Content(
-					mediaType = MediaType.TEXT_PLAIN,
-					schema = @Schema(
-						type = "string"
-					)
-				)
-			)
-		}
-	)
-	@ApiErrors({ApiError.NON_PRODUCTION, ApiError.INVALID_DATA})
-	public String getMnemonic(@QueryParam("entropy") String suppliedEntropy) {
-		if (Settings.getInstance().isApiRestricted())
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
-
-		/*
-		 * BIP39 word lists have 2048 entries so can be represented by 11 bits.
-		 * UUID (128bits) and another 4 bits gives 132 bits.
-		 * 132 bits, divided by 11, gives 12 words.
-		 */
-		byte[] entropy;
-		if (suppliedEntropy != null) {
-			// Use caller-supplied entropy input
-			try {
-				entropy = Base58.decode(suppliedEntropy);
-			} catch (NumberFormatException e) {
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-			}
-
-			// Must be 16-bytes
-			if (entropy.length != 16)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-		} else {
-			// Generate entropy internally
-			UUID uuid = UUID.randomUUID();
-
-			byte[] uuidMSB = Longs.toByteArray(uuid.getMostSignificantBits());
-			byte[] uuidLSB = Longs.toByteArray(uuid.getLeastSignificantBits());
-			entropy = Bytes.concat(uuidMSB, uuidLSB);
-		}
-
-		// Use SHA256 to generate more bits
-		byte[] hash = Crypto.digest(entropy);
-
-		// Append first 4 bits from hash to end. (Actually 8 bits but we only use 4).
-		byte checksum = (byte) (hash[0] & 0xf0);
-		entropy = Bytes.concat(entropy, new byte[] {
-			checksum
-		});
-
-		return BIP39.encode(entropy, "en");
-	}
-
-	@POST
-	@Path("/mnemonic")
-	@Operation(
-		summary = "Calculate binary entropy from 12-word BIP39 mnemonic",
-		description = "Returns the base58-encoded binary form, or \"false\" if mnemonic is invalid.",
-		requestBody = @RequestBody(
-			required = true,
-			content = @Content(
-				mediaType = MediaType.TEXT_PLAIN,
-				schema = @Schema(
-					type = "string"
-				)
-			)
-		),
-		responses = {
-			@ApiResponse(
-				description = "entropy in base58",
-				content = @Content(
-					mediaType = MediaType.TEXT_PLAIN,
-					schema = @Schema(
-						type = "string"
-					)
-				)
-			)
-		}
-	)
-	@ApiErrors({ApiError.NON_PRODUCTION})
-	public String fromMnemonic(String mnemonic) {
-		if (Settings.getInstance().isApiRestricted())
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
-
-		if (mnemonic.isEmpty())
-			return "false";
-
-		// Strip leading/trailing whitespace if any
-		mnemonic = mnemonic.trim();
-
-		String[] phraseWords = mnemonic.split(" ");
-		if (phraseWords.length != 12)
-			return "false";
-
-		// Convert BIP39 mnemonic to binary
-		byte[] binary = BIP39.decode(phraseWords, "en");
-		if (binary == null)
-			return "false";
-
-		byte[] entropy = Arrays.copyOf(binary, 16); // 132 bits is 16.5 bytes, but we're discarding checksum nybble
-
-		byte checksumNybble = (byte) (binary[16] & 0xf0);
-		byte[] checksum = Crypto.digest(entropy);
-		if (checksumNybble != (byte) (checksum[0] & 0xf0))
-			return "false";
-
-		return Base58.encode(entropy);
-	}
-
 	@POST
 	@Path("/privatekey")
 	@Operation(

src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java

@@ -115,6 +115,9 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 	}
 
 	private void onNotify(Session session, ChatTransactionData chatTransactionData, List<String> involvingAddresses) {
+		if (chatTransactionData == null)
+			return;
+
 		// We only want direct/non-group messages where sender/recipient match our addresses
 		String recipient = chatTransactionData.getRecipient();
 		if (recipient == null)

src/main/java/org/qortal/at/AT.java

@@ -1,5 +1,7 @@
 package org.qortal.at;
 
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import org.ciyam.at.MachineState;
@@ -56,12 +58,12 @@ public class AT {
 
 		this.atData = new ATData(atAddress, creatorPublicKey, creation, machineState.version, assetId, codeBytes, codeHash,
 				machineState.isSleeping(), machineState.getSleepUntilHeight(), machineState.isFinished(), machineState.hadFatalError(),
-				machineState.isFrozen(), machineState.getFrozenBalance());
+				machineState.isFrozen(), machineState.getFrozenBalance(), null);
 
 		byte[] stateData = machineState.toBytes();
 		byte[] stateHash = Crypto.digest(stateData);
 
-		this.atStateData = new ATStateData(atAddress, height, stateData, stateHash, 0L, true);
+		this.atStateData = new ATStateData(atAddress, height, stateData, stateHash, 0L, true, null);
 	}
 
 	// Getters / setters
@@ -84,13 +86,28 @@ public class AT {
 		this.repository.getATRepository().delete(this.atData.getATAddress());
 	}
 
+	/**
+	 * Potentially execute AT.
+	 * <p>
+	 * Note that sleep-until-message support might set/reset
+	 * sleep-related flags/values.
+	 * <p>
+	 * {@link #getATStateData()} will return null if nothing happened.
+	 * <p>
+	 * @param blockHeight
+	 * @param blockTimestamp
+	 * @return AT-generated transactions, possibly empty
+	 * @throws DataException
+	 */
 	public List<AtTransaction> run(int blockHeight, long blockTimestamp) throws DataException {
 		String atAddress = this.atData.getATAddress();
 
 		QortalATAPI api = new QortalATAPI(repository, this.atData, blockTimestamp);
 		QortalAtLoggerFactory loggerFactory = QortalAtLoggerFactory.getInstance();
 
-		byte[] codeBytes = this.atData.getCodeBytes();
+		if (!api.willExecute(blockHeight))
+			// this.atStateData will be null
+			return Collections.emptyList();
 
 		// Fetch latest ATStateData for this AT
 		ATStateData latestAtStateData = this.repository.getATRepository().getLatestATState(atAddress);
@@ -100,8 +117,10 @@ public class AT {
 			throw new IllegalStateException("No previous AT state data found");
 
 		// [Re]create AT machine state using AT state data or from scratch as applicable
+		byte[] codeBytes = this.atData.getCodeBytes();
 		MachineState state = MachineState.fromBytes(api, loggerFactory, latestAtStateData.getStateData(), codeBytes);
 		try {
+			api.preExecute(state);
 			state.execute();
 		} catch (Exception e) {
 			throw new DataException(String.format("Uncaught exception while running AT '%s'", atAddress), e);
@@ -109,9 +128,18 @@ public class AT {
 
 		byte[] stateData = state.toBytes();
 		byte[] stateHash = Crypto.digest(stateData);
-		long atFees = api.calcFinalFees(state);
 
-		this.atStateData = new ATStateData(atAddress, blockHeight, stateData, stateHash, atFees, false);
+		// Nothing happened?
+		if (state.getSteps() == 0 && Arrays.equals(stateHash, latestAtStateData.getStateHash()))
+			// We currently want to execute frozen ATs, to maintain backwards support.
+			if (state.isFrozen() == false)
+				// this.atStateData will be null
+				return Collections.emptyList();
+
+		long atFees = api.calcFinalFees(state);
+		Long sleepUntilMessageTimestamp = this.atData.getSleepUntilMessageTimestamp();
+
+		this.atStateData = new ATStateData(atAddress, blockHeight, stateData, stateHash, atFees, false, sleepUntilMessageTimestamp);
 
 		return api.getTransactions();
 	}
@@ -130,6 +158,10 @@ public class AT {
 		this.atData.setHadFatalError(state.hadFatalError());
 		this.atData.setIsFrozen(state.isFrozen());
 		this.atData.setFrozenBalance(state.getFrozenBalance());
+
+		// Special sleep-until-message support
+		this.atData.setSleepUntilMessageTimestamp(this.atStateData.getSleepUntilMessageTimestamp());
+
 		this.repository.getATRepository().save(this.atData);
 	}
 
@@ -157,6 +189,10 @@ public class AT {
 		this.atData.setHadFatalError(state.hadFatalError());
 		this.atData.setIsFrozen(state.isFrozen());
 		this.atData.setFrozenBalance(state.getFrozenBalance());
+
+		// Special sleep-until-message support
+		this.atData.setSleepUntilMessageTimestamp(previousStateData.getSleepUntilMessageTimestamp());
+
 		this.repository.getATRepository().save(this.atData);
 	}
 

src/main/java/org/qortal/at/QortalATAPI.java

@@ -32,6 +32,7 @@ import org.qortal.group.Group;
 import org.qortal.repository.ATRepository;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.repository.ATRepository.NextTransactionInfo;
 import org.qortal.transaction.AtTransaction;
 import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.utils.Base58;
@@ -74,8 +75,45 @@ public class QortalATAPI extends API {
 		return this.transactions;
 	}
 
-	public long calcFinalFees(MachineState state) {
-		return state.getSteps() * this.ciyamAtSettings.feePerStep;
+	public boolean willExecute(int blockHeight) throws DataException {
+		// Sleep-until-message/height checking
+		Long sleepUntilMessageTimestamp = this.atData.getSleepUntilMessageTimestamp();
+
+		if (sleepUntilMessageTimestamp != null) {
+			// Quicker to check height, if sleep-until-height also active
+			Integer sleepUntilHeight = this.atData.getSleepUntilHeight();
+
+			boolean wakeDueToHeight = sleepUntilHeight != null && sleepUntilHeight != 0 && blockHeight >= sleepUntilHeight;
+
+			boolean wakeDueToMessage = false;
+			if (!wakeDueToHeight) {
+				// No avoiding asking repository
+				Timestamp previousTxTimestamp = new Timestamp(sleepUntilMessageTimestamp);
+				NextTransactionInfo nextTransactionInfo = this.repository.getATRepository().findNextTransaction(this.atData.getATAddress(),
+						previousTxTimestamp.blockHeight,
+						previousTxTimestamp.transactionSequence);
+
+				wakeDueToMessage = nextTransactionInfo != null;
+			}
+
+			// Can we skip?
+			if (!wakeDueToHeight && !wakeDueToMessage)
+				return false;
+		}
+
+		return true;
+	}
+
+	public void preExecute(MachineState state) {
+		// Sleep-until-message/height checking
+		Long sleepUntilMessageTimestamp = this.atData.getSleepUntilMessageTimestamp();
+
+		if (sleepUntilMessageTimestamp != null) {
+			// We've passed checks, so clear sleep-related flags/values
+			this.setIsSleeping(state, false);
+			this.setSleepUntilHeight(state, 0);
+			this.atData.setSleepUntilMessageTimestamp(null);
+		}
 	}
 
 	// Inherited methods from CIYAM AT API
@@ -412,6 +450,10 @@ public class QortalATAPI extends API {
 
 	// Utility methods
 
+	public long calcFinalFees(MachineState state) {
+		return state.getSteps() * this.ciyamAtSettings.feePerStep;
+	}
+
 	/** Returns partial transaction signature, used to verify we're operating on the same transaction and not naively using block height & sequence. */
 	public static byte[] partialSignature(byte[] fullSignature) {
 		return Arrays.copyOfRange(fullSignature, 8, 32);
@@ -460,6 +502,15 @@ public class QortalATAPI extends API {
 		}
 	}
 
+	/*package*/ void sleepUntilMessageOrHeight(MachineState state, long txTimestamp, Long sleepUntilHeight) {
+		this.setIsSleeping(state, true);
+
+		this.atData.setSleepUntilMessageTimestamp(txTimestamp);
+
+		if (sleepUntilHeight != null)
+			this.setSleepUntilHeight(state, sleepUntilHeight.intValue());
+	}
+
 	/** Returns AT's account */
 	/* package */ Account getATAccount() {
 		return new Account(this.repository, this.atData.getATAddress());

src/main/java/org/qortal/at/QortalFunctionCode.java

@@ -84,6 +84,43 @@ public enum QortalFunctionCode {
 			api.setB(state, bBytes);
 		}
 	},
+	/**
+	 * Sleep AT until a new message arrives after 'tx-timestamp'.<br>
+	 * <tt>0x0503 tx-timestamp</tt>
+	 */
+	SLEEP_UNTIL_MESSAGE(0x0503, 1, false) {
+		@Override
+		protected void postCheckExecute(FunctionData functionData, MachineState state, short rawFunctionCode) throws ExecutionException {
+			if (functionData.value1 <= 0)
+				return;
+
+			long txTimestamp = functionData.value1;
+
+			QortalATAPI api = (QortalATAPI) state.getAPI();
+			api.sleepUntilMessageOrHeight(state, txTimestamp, null);
+		}
+	},
+	/**
+	 * Sleep AT until a new message arrives, after 'tx-timestamp', or height reached.<br>
+	 * <tt>0x0504 tx-timestamp height</tt>
+	 */
+	SLEEP_UNTIL_MESSAGE_OR_HEIGHT(0x0504, 2, false) {
+		@Override
+		protected void postCheckExecute(FunctionData functionData, MachineState state, short rawFunctionCode) throws ExecutionException {
+			if (functionData.value1 <= 0)
+				return;
+
+			long txTimestamp = functionData.value1;
+
+			if (functionData.value2 <= 0)
+				return;
+
+			long sleepUntilHeight = functionData.value2;
+
+			QortalATAPI api = (QortalATAPI) state.getAPI();
+			api.sleepUntilMessageOrHeight(state, txTimestamp, sleepUntilHeight);
+		}
+	},
 	/**
 	 * Convert address in B to 20-byte value in LSB of B1, and all of B2 & B3.<br>
 	 * <tt>0x0510</tt>

src/main/java/org/qortal/block/Block.java

@@ -1092,9 +1092,14 @@ public class Block {
 			// Create repository savepoint here so we can rollback to it after testing transactions
 			repository.setSavepoint();
 
-			if (this.blockData.getHeight() == 212937)
+			if (this.blockData.getHeight() == 212937) {
 				// Apply fix for block 212937 but fix will be rolled back before we exit method
 				Block212937.processFix(this);
+			}
+			else if (InvalidNameRegistrationBlocks.isAffectedBlock(this.blockData.getHeight())) {
+				// Apply fix for affected name registration blocks, but fix will be rolled back before we exit method
+				InvalidNameRegistrationBlocks.processFix(this);
+			}
 
 			for (Transaction transaction : this.getTransactions()) {
 				TransactionData transactionData = transaction.getTransactionData();
@@ -1133,7 +1138,7 @@ public class Block {
 				// Check transaction can even be processed
 				validationResult = transaction.isProcessable();
 				if (validationResult != Transaction.ValidationResult.OK) {
-					LOGGER.debug(String.format("Error during transaction validation, tx %s: %s", Base58.encode(transactionData.getSignature()), validationResult.name()));
+					LOGGER.info(String.format("Error during transaction validation, tx %s: %s", Base58.encode(transactionData.getSignature()), validationResult.name()));
 					return ValidationResult.TRANSACTION_INVALID;
 				}
 
@@ -1247,12 +1252,13 @@ public class Block {
 		for (ATData atData : executableATs) {
 			AT at = new AT(this.repository, atData);
 			List<AtTransaction> atTransactions = at.run(this.blockData.getHeight(), this.blockData.getTimestamp());
+			ATStateData atStateData = at.getATStateData();
+			// Didn't execute? (e.g. sleeping)
+			if (atStateData == null)
+				continue;
 
 			allAtTransactions.addAll(atTransactions);
-
-			ATStateData atStateData = at.getATStateData();
 			this.ourAtStates.add(atStateData);
-
 			this.ourAtFees += atStateData.getFees();
 		}
 
@@ -1281,6 +1287,21 @@ public class Block {
 		return mintingAccount.canMint();
 	}
 
+	/**
+	 * Pre-process block, and its transactions.
+	 * This allows for any database integrity checks prior to validation.
+	 * This is called before isValid() and process()
+	 *
+	 * @throws DataException
+	 */
+	public void preProcess() throws DataException {
+		List<Transaction> blocksTransactions = this.getTransactions();
+
+		for (Transaction transaction : blocksTransactions) {
+			transaction.preProcess();
+		}
+	}
+
 	/**
 	 * Process block, and its transactions, adding them to the blockchain.
 	 * 

src/main/java/org/qortal/block/InvalidNameRegistrationBlocks.java

@@ -0,0 +1,114 @@
+package org.qortal.block;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.naming.Name;
+import org.qortal.repository.DataException;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Invalid Name Registration Blocks
+ * <p>
+ * A node minted a version of block 535658 that contained one transaction:
+ * a REGISTER_NAME transaction that attempted to register a name that was already registered.
+ * <p>
+ * This invalid transaction made block 535658 (rightly) invalid to several nodes,
+ * which refused to use that block.
+ * However, it seems there were no other nodes minting an alternative, valid block at that time
+ * and so the chain stalled for several nodes in the network.
+ * <p>
+ * Additionally, the invalid block 535658 affected all new installations, regardless of whether
+ * they synchronized from scratch (block 1) or used an 'official release' bootstrap.
+ * <p>
+ * The diagnosis found the following:
+ * - The original problem occurred in block 535205 where for some unknown reason many nodes didn't
+ *   add the name from a REGISTER_NAME transaction to their Names table.
+ * - As a result, those nodes had a corrupt db, because they weren't holding a record of the name.
+ * - This invalid db then caused them to treat a candidate for block 535658 as valid when it
+ *   should have been invalid.
+ * - As such, the chain continued on with a technically invalid block in it, for a subset of the network
+ * <p>
+ * As with block 212937, there were three options, but the only feasible one was to apply edits to block
+ * 535658 to make it valid. There were several cross-chain trades completed after this block, so doing
+ * any kind of rollback was out of the question.
+ * <p>
+ * To complicate things further, a custom data field was used for the first REGISTER_NAME transaction,
+ * and the default data field was used for the second. So it was important that all nodes ended up with
+ * the exact same data regardless of how they arrived there.
+ * <p>
+ * The invalid block 535658 signature is: <tt>3oiuDhok...NdXvCLEV</tt>.
+ * <p>
+ * The invalid transaction in block 212937 is:
+ * <p>
+ * <code><pre>
+	 {
+		 "type": "REGISTER_NAME",
+		 "timestamp": 1630739437517,
+		 "reference": "4peRechwSPxP6UkRj9Y8ox9YxkWb34sWk5zyMc1WyMxEsACxD4Gmm7LZVsQ6Skpze8QCSBMZasvEZg6RgdqkyADW",
+		 "fee": "0.00100000",
+		 "signature": "2t1CryCog8KPDBarzY5fDCKu499nfnUcGrz4Lz4w5wNb5nWqm7y126P48dChYY7huhufcBV3RJPkgKP4Ywxc1gXx",
+		 "txGroupId": 0,
+		 "blockHeight": 535658,
+		 "approvalStatus": "NOT_REQUIRED",
+		 "creatorAddress": "Qbx9ojxv7XNi1xDMWzzw7xDvd1zYW6SKFB",
+		 "registrantPublicKey": "HJqGEf6cW695Xun4ydhkB2excGFwsDxznhNCRHZStyyx",
+		 "name": "Qplay",
+		 "data": "Registered Name on the Qortal Chain"
+	 }
+   </pre></code>
+ * <p>
+ * Account <tt>Qbx9ojxv7XNi1xDMWzzw7xDvd1zYW6SKFB</tt> attempted to register the name <tt>Qplay</tt>
+ * when they had already registered it 12 hours before in block <tt>535205</tt>.
+ * <p>
+ * However, on the broken DB nodes, their Names table was missing a record for the `Qplay` name
+ * which was sufficient to make the transaction valid.
+ *
+ * This problem then occurred two more times, in blocks 536140 and 541334
+ * To reduce duplication, I have combined all three block fixes into a single class
+ *
+ */
+public final class InvalidNameRegistrationBlocks {
+
+	private static final Logger LOGGER = LogManager.getLogger(InvalidNameRegistrationBlocks.class);
+
+	public static Map<Integer, String> invalidBlocksNamesMap = new HashMap<Integer, String>()
+	{
+		{
+			put(535658, "Qplay");
+			put(536140, "Qweb");
+			put(541334, "Qithub");
+		}
+	};
+
+	private InvalidNameRegistrationBlocks() {
+		/* Do not instantiate */
+	}
+
+	public static boolean isAffectedBlock(int height) {
+		return (invalidBlocksNamesMap.containsKey(height));
+	}
+
+	public static void processFix(Block block) throws DataException {
+		Integer blockHeight = block.getBlockData().getHeight();
+		String invalidName = invalidBlocksNamesMap.get(blockHeight);
+		if (invalidName == null) {
+			throw new DataException(String.format("Unable to lookup invalid name for block height %d", blockHeight));
+		}
+
+		// Unregister the existing name record if it exists
+		// This ensures that the duplicate name is considered valid, and therefore
+		// the second (i.e. duplicate) REGISTER_NAME transaction data is applied.
+		// Both were issued by the same user account, so there is no conflict.
+		Name name = new Name(block.repository, invalidName);
+		name.unregister();
+
+		LOGGER.debug("Applied name registration patch for block {}", blockHeight);
+	}
+
+	// Note:
+	// There is no need to write an orphanFix() method, as we do not have
+	// the necessary ATStatesData to orphan back this far anyway
+
+}

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

@@ -44,6 +44,9 @@ public class BlockMinter extends Thread {
 	private static Long lastLogTimestamp;
 	private static Long logTimeout;
 
+	// Recovery
+	public static final long INVALID_BLOCK_RECOVERY_TIMEOUT = 10 * 60 * 1000L; // ms
+
 	// Constructors
 
 	public BlockMinter() {
@@ -144,9 +147,25 @@ public class BlockMinter extends Thread {
 				if (peers.size() < Settings.getInstance().getMinBlockchainPeers())
 					continue;
 
+				// If we are stuck on an invalid block, we should allow an alternative to be minted
+				boolean recoverInvalidBlock = false;
+				if (Synchronizer.getInstance().timeInvalidBlockLastReceived != null) {
+					// We've had at least one invalid block
+					long timeSinceLastValidBlock = NTP.getTime() - Synchronizer.getInstance().timeValidBlockLastReceived;
+					long timeSinceLastInvalidBlock = NTP.getTime() - Synchronizer.getInstance().timeInvalidBlockLastReceived;
+					if (timeSinceLastValidBlock > INVALID_BLOCK_RECOVERY_TIMEOUT) {
+						if (timeSinceLastInvalidBlock < INVALID_BLOCK_RECOVERY_TIMEOUT) {
+							// Last valid block was more than 10 mins ago, but we've had an invalid block since then
+							// Assume that the chain has stalled because there is no alternative valid candidate
+							// Enter recovery mode to allow alternative, valid candidates to be minted
+							recoverInvalidBlock = true;
+						}
+					}
+				}
+
 				// If our latest block isn't recent then we need to synchronize instead of minting, unless we're in recovery mode.
 				if (!peers.isEmpty() && lastBlockData.getTimestamp() < minLatestBlockTimestamp)
-					if (Controller.getInstance().getRecoveryMode() == false)
+					if (Controller.getInstance().getRecoveryMode() == false && recoverInvalidBlock == false)
 						continue;
 
 				// There are enough peers with a recent block and our latest block is recent
@@ -230,6 +249,8 @@ public class BlockMinter extends Thread {
 						if (testBlock.isTimestampValid() != ValidationResult.OK)
 							continue;
 
+						testBlock.preProcess();
+
 						// Is new block valid yet? (Before adding unconfirmed transactions)
 						ValidationResult result = testBlock.isValid();
 						if (result != ValidationResult.OK) {

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

@@ -46,6 +46,7 @@ import org.qortal.block.Block;
 import org.qortal.block.BlockChain;
 import org.qortal.block.BlockChain.BlockTimingByHeight;
 import org.qortal.controller.Synchronizer.SynchronizationResult;
+import org.qortal.controller.repository.NamesDatabaseIntegrityCheck;
 import org.qortal.controller.tradebot.TradeBot;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.account.MintingAccountData;
@@ -259,17 +260,29 @@ public class Controller extends Thread {
 			throw new RuntimeException("Can't read build.properties resource", e);
 		}
 
+		// Determine build timestamp
 		String buildTimestampProperty = properties.getProperty("build.timestamp");
-		if (buildTimestampProperty == null)
+		if (buildTimestampProperty == null) {
 			throw new RuntimeException("Can't read build.timestamp from build.properties resource");
-
-		this.buildTimestamp = LocalDateTime.parse(buildTimestampProperty, DateTimeFormatter.ofPattern("yyyyMMddHHmmss")).toEpochSecond(ZoneOffset.UTC);
+		}
+		if (buildTimestampProperty.startsWith("$")) {
+			// Maven vars haven't been replaced - this was most likely built using an IDE, not via mvn package
+			this.buildTimestamp = System.currentTimeMillis();
+			buildTimestampProperty = "unknown";
+		} else {
+			this.buildTimestamp = LocalDateTime.parse(buildTimestampProperty, DateTimeFormatter.ofPattern("yyyyMMddHHmmss")).toEpochSecond(ZoneOffset.UTC);
+		}
 		LOGGER.info(String.format("Build timestamp: %s", buildTimestampProperty));
 
+		// Determine build version
 		String buildVersionProperty = properties.getProperty("build.version");
-		if (buildVersionProperty == null)
+		if (buildVersionProperty == null) {
 			throw new RuntimeException("Can't read build.version from build.properties resource");
-
+		}
+		if (buildVersionProperty.contains("${git.commit.id.abbrev}")) {
+			// Maven vars haven't been replaced - this was most likely built using an IDE, not via mvn package
+			buildVersionProperty = buildVersionProperty.replace("${git.commit.id.abbrev}", "debug");
+		}
 		this.buildVersion = VERSION_PREFIX + buildVersionProperty;
 		LOGGER.info(String.format("Build version: %s", this.buildVersion));
 
@@ -416,6 +429,11 @@ public class Controller extends Thread {
 			return; // Not System.exit() so that GUI can display error
 		}
 
+		// Rebuild Names table and check database integrity
+		NamesDatabaseIntegrityCheck namesDatabaseIntegrityCheck = new NamesDatabaseIntegrityCheck();
+		namesDatabaseIntegrityCheck.rebuildAllNames();
+		namesDatabaseIntegrityCheck.runIntegrityCheck();
+
 		LOGGER.info("Validating blockchain");
 		try {
 			BlockChain.validate();
@@ -678,7 +696,7 @@ public class Controller extends Thread {
 
 		final int peersRemoved = peersBeforeComparison - peers.size();
 		if (peersRemoved > 0 && peers.size() > 0)
-			LOGGER.info(String.format("Ignoring %d peers on inferior chains. Peers remaining: %d", peersRemoved, peers.size()));
+			LOGGER.debug(String.format("Ignoring %d peers on inferior chains. Peers remaining: %d", peersRemoved, peers.size()));
 
 		if (peers.isEmpty())
 			return;
@@ -687,7 +705,7 @@ public class Controller extends Thread {
 			StringBuilder finalPeersString = new StringBuilder();
 			for (Peer peer : peers)
 				finalPeersString = finalPeersString.length() > 0 ? finalPeersString.append(", ").append(peer) : finalPeersString.append(peer);
-			LOGGER.info(String.format("Choosing random peer from: [%s]", finalPeersString.toString()));
+			LOGGER.debug(String.format("Choosing random peer from: [%s]", finalPeersString.toString()));
 		}
 
 		// Pick random peer to sync with
@@ -710,6 +728,7 @@ public class Controller extends Thread {
 				hasStatusChanged = true;
 			}
 		}
+		peer.setSyncInProgress(true);
 
 		if (hasStatusChanged)
 			updateSysTray();
@@ -789,6 +808,7 @@ public class Controller extends Thread {
 			return syncResult;
 		} finally {
 			isSynchronizing = false;
+			peer.setSyncInProgress(false);
 		}
 	}
 
@@ -840,6 +860,7 @@ public class Controller extends Thread {
 	private void updateSysTray() {
 		if (NTP.getTime() == null) {
 			SysTray.getInstance().setToolTipText(Translator.INSTANCE.translate("SysTray", "SYNCHRONIZING_CLOCK"));
+			SysTray.getInstance().setTrayIcon(1);
 			return;
 		}
 
@@ -853,17 +874,25 @@ public class Controller extends Thread {
 		String actionText;
 
 		synchronized (this.syncLock) {
-			if (this.isMintingPossible)
+			if (this.isMintingPossible) {
 				actionText = Translator.INSTANCE.translate("SysTray", "MINTING_ENABLED");
-			else if (this.isSynchronizing)
+				SysTray.getInstance().setTrayIcon(2);
+			}
+			else if (this.isSynchronizing) {
 				actionText = String.format("%s - %d%%", Translator.INSTANCE.translate("SysTray", "SYNCHRONIZING_BLOCKCHAIN"), this.syncPercent);
-			else if (numberOfPeers < Settings.getInstance().getMinBlockchainPeers())
+				SysTray.getInstance().setTrayIcon(3);
+			}
+			else if (numberOfPeers < Settings.getInstance().getMinBlockchainPeers()) {
 				actionText = Translator.INSTANCE.translate("SysTray", "CONNECTING");
-			else
+				SysTray.getInstance().setTrayIcon(3);
+			}
+			else {
 				actionText = Translator.INSTANCE.translate("SysTray", "MINTING_DISABLED");
+				SysTray.getInstance().setTrayIcon(4);
+			}
 		}
 
-		String tooltip = String.format("%s - %d %s - %s %d", actionText, numberOfPeers, connectionsText, heightText, height) + "\n" + String.format("Build version: %s", this.buildVersion);
+		String tooltip = String.format("%s - %d %s - %s %d", actionText, numberOfPeers, connectionsText, heightText, height) + "\n" + String.format("%s: %s", Translator.INSTANCE.translate("SysTray", "BUILD_VERSION"), this.buildVersion);
 		SysTray.getInstance().setToolTipText(tooltip);
 
 		this.callbackExecutor.execute(() -> {
@@ -883,14 +912,19 @@ public class Controller extends Thread {
 
 			List<TransactionData> transactions = repository.getTransactionRepository().getUnconfirmedTransactions();
 
+			int deletedCount = 0;
 			for (TransactionData transactionData : transactions) {
 				Transaction transaction = Transaction.fromData(repository, transactionData);
 
 				if (now >= transaction.getDeadline()) {
-					LOGGER.info(() -> String.format("Deleting expired, unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
+					LOGGER.debug(() -> String.format("Deleting expired, unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
 					repository.getTransactionRepository().delete(transactionData);
+					deletedCount++;
 				}
 			}
+			if (deletedCount > 0) {
+				LOGGER.info(String.format("Deleted %d expired, unconfirmed transaction%s", deletedCount, (deletedCount == 1 ? "" : "s")));
+			}
 
 			repository.saveChanges();
 		} catch (DataException e) {

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

@@ -3,12 +3,9 @@ package org.qortal.controller;
 import java.math.BigInteger;
 import java.text.DecimalFormat;
 import java.text.NumberFormat;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
+import java.util.*;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.stream.Collectors;
-import java.util.Iterator;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -59,6 +56,14 @@ public class Synchronizer {
 	private static final int MAXIMUM_REQUEST_SIZE = 200; // XXX move to Settings?
 
 
+	// Keep track of the size of the last re-org, so it can be logged
+	private int lastReorgSize;
+
+	// Keep track of invalid blocks so that we don't keep trying to sync them
+	private Map<String, Long> invalidBlockSignatures = Collections.synchronizedMap(new HashMap<>());
+	public Long timeValidBlockLastReceived = null;
+	public Long timeInvalidBlockLastReceived = null;
+
 	private static Synchronizer instance;
 
 	public enum SynchronizationResult {
@@ -139,7 +144,7 @@ public class Synchronizer {
 
 				if (wereNewRequestsMade) {
 					final long totalTimeTaken = System.currentTimeMillis() - startTime;
-					LOGGER.info(String.format("Finished searching for common blocks with %d peer%s. Found: %d. Total time taken: %d ms", peers.size(), (peers.size() != 1 ? "s" : ""), commonBlocksFound, totalTimeTaken));
+					LOGGER.debug(String.format("Finished searching for common blocks with %d peer%s. Found: %d. Total time taken: %d ms", peers.size(), (peers.size() != 1 ? "s" : ""), commonBlocksFound, totalTimeTaken));
 				}
 
 				return SynchronizationResult.OK;
@@ -334,6 +339,12 @@ public class Synchronizer {
 							}
 						}
 
+						// Ignore this peer if it holds an invalid block
+						if (this.containsInvalidBlockSummary(peer.getCommonBlockData().getBlockSummariesAfterCommonBlock())) {
+							LOGGER.debug("Ignoring peer %s because it holds an invalid block", peer);
+							peers.remove(peer);
+						}
+
 						// Reduce minChainLength if needed. If we don't have any blocks, this peer will be excluded from chain weight comparisons later in the process, so we shouldn't update minChainLength
 						List <BlockSummaryData> peerBlockSummaries = peer.getCommonBlockData().getBlockSummariesAfterCommonBlock();
 						if (peerBlockSummaries != null && peerBlockSummaries.size() > 0)
@@ -477,6 +488,71 @@ public class Synchronizer {
 	}
 
 
+
+	/* Invalid block signature tracking */
+
+	private void addInvalidBlockSignature(byte[] signature) {
+		Long now = NTP.getTime();
+		if (now == null) {
+			return;
+		}
+
+		// Add or update existing entry
+		String sig58 = Base58.encode(signature);
+		invalidBlockSignatures.put(sig58, now);
+	}
+	private void deleteOlderInvalidSignatures(Long now) {
+		if (now == null) {
+			return;
+		}
+
+		// Delete signatures with older timestamps
+		Iterator it = invalidBlockSignatures.entrySet().iterator();
+		while (it.hasNext()) {
+			Map.Entry pair = (Map.Entry)it.next();
+			Long lastSeen = (Long) pair.getValue();
+
+			// Remove signature if we haven't seen it for more than 1 hour
+			if (now - lastSeen > 60 * 60 * 1000L) {
+				it.remove();
+			}
+		}
+	}
+	private boolean containsInvalidBlockSummary(List<BlockSummaryData> blockSummaries) {
+		if (blockSummaries == null || invalidBlockSignatures == null) {
+			return false;
+		}
+
+		// Loop through our known invalid blocks and check each one against supplied block summaries
+		for (String invalidSignature58 : invalidBlockSignatures.keySet()) {
+			byte[] invalidSignature = Base58.decode(invalidSignature58);
+			for (BlockSummaryData blockSummary : blockSummaries) {
+				byte[] signature = blockSummary.getSignature();
+				if (Arrays.equals(signature, invalidSignature)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+	private boolean containsInvalidBlockSignature(List<byte[]> blockSignatures) {
+		if (blockSignatures == null || invalidBlockSignatures == null) {
+			return false;
+		}
+
+		// Loop through our known invalid blocks and check each one against supplied block signatures
+		for (String invalidSignature58 : invalidBlockSignatures.keySet()) {
+			byte[] invalidSignature = Base58.decode(invalidSignature58);
+			for (byte[] signature : blockSignatures) {
+				if (Arrays.equals(signature, invalidSignature)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+
 	/**
 	 * Attempt to synchronize blockchain with peer.
 	 * <p>
@@ -506,9 +582,31 @@ public class Synchronizer {
 					byte[] peersLastBlockSignature = peerChainTipData.getLastBlockSignature();
 
 					byte[] ourLastBlockSignature = ourLatestBlockData.getSignature();
-					LOGGER.debug(String.format("Synchronizing with peer %s at height %d, sig %.8s, ts %d; our height %d, sig %.8s, ts %d", peer,
+					String syncString = String.format("Synchronizing with peer %s at height %d, sig %.8s, ts %d; our height %d, sig %.8s, ts %d", peer,
 							peerHeight, Base58.encode(peersLastBlockSignature), peer.getChainTipData().getLastBlockTimestamp(),
-							ourInitialHeight, Base58.encode(ourLastBlockSignature), ourLatestBlockData.getTimestamp()));
+							ourInitialHeight, Base58.encode(ourLastBlockSignature), ourLatestBlockData.getTimestamp());
+
+					// If our latest block is very old, we should log that we're attempting to sync with a peer
+					// Otherwise, it can appear as though nothing is happening for a while after launch
+					final Long minLatestBlockTimestamp = Controller.getMinimumLatestBlockTimestamp();
+					if (minLatestBlockTimestamp != null && ourLatestBlockData.getTimestamp() < minLatestBlockTimestamp) {
+						LOGGER.info(syncString);
+					}
+					else {
+						LOGGER.debug(syncString);
+					}
+
+					// Reset last re-org size as we are starting a new sync round
+					this.lastReorgSize = 0;
+
+					// Set the initial value of timeValidBlockLastReceived if it's null
+					Long now = NTP.getTime();
+					if (this.timeValidBlockLastReceived == null) {
+						this.timeValidBlockLastReceived = now;
+					}
+
+					// Delete invalid signatures with older timestamps
+					this.deleteOlderInvalidSignatures(now);
 
 					List<BlockSummaryData> peerBlockSummaries = new ArrayList<>();
 					SynchronizationResult findCommonBlockResult = fetchSummariesFromCommonBlock(repository, peer, ourInitialHeight, force, peerBlockSummaries, true);
@@ -567,10 +665,19 @@ public class Synchronizer {
 					// Commit
 					repository.saveChanges();
 
+					// Create string for logging
 					final BlockData newLatestBlockData = repository.getBlockRepository().getLastBlock();
-					LOGGER.info(String.format("Synchronized with peer %s to height %d, sig %.8s, ts: %d", peer,
+					String syncLog = String.format("Synchronized with peer %s to height %d, sig %.8s, ts: %d", peer,
 							newLatestBlockData.getHeight(), Base58.encode(newLatestBlockData.getSignature()),
-							newLatestBlockData.getTimestamp()));
+							newLatestBlockData.getTimestamp());
+
+					// Append re-org info
+					if (this.lastReorgSize > 0) {
+						syncLog = syncLog.concat(String.format(", size: %d", this.lastReorgSize));
+					}
+
+					// Log sync info
+					LOGGER.info(syncLog);
 
 					return SynchronizationResult.OK;
 				} finally {
@@ -849,6 +956,12 @@ public class Synchronizer {
 				break;
 			}
 
+			// Catch a block with an invalid signature before orphaning, so that we retain our existing valid candidate
+			if (this.containsInvalidBlockSignature(peerBlockSignatures)) {
+				LOGGER.info(String.format("Peer %s sent invalid block signature: %.8s", peer, Base58.encode(latestPeerSignature)));
+				return SynchronizationResult.INVALID_DATA;
+			}
+
 			byte[] nextPeerSignature = peerBlockSignatures.get(0);
 			int nextHeight = height + 1;
 
@@ -924,6 +1037,7 @@ public class Synchronizer {
 		// Unwind to common block (unless common block is our latest block)
 		int ourHeight = ourInitialHeight;
 		LOGGER.debug(String.format("Orphaning blocks back to common block height %d, sig %.8s. Our height: %d", commonBlockHeight, commonBlockSig58, ourHeight));
+		int reorgSize = ourHeight - commonBlockHeight;
 
 		BlockData orphanBlockData = repository.getBlockRepository().fromHeight(ourInitialHeight);
 		while (ourHeight > commonBlockHeight) {
@@ -950,13 +1064,20 @@ public class Synchronizer {
 			if (Controller.isStopping())
 				return SynchronizationResult.SHUTTING_DOWN;
 
+			newBlock.preProcess();
+
 			ValidationResult blockResult = newBlock.isValid();
 			if (blockResult != ValidationResult.OK) {
 				LOGGER.info(String.format("Peer %s sent invalid block for height %d, sig %.8s: %s", peer,
 						newBlock.getBlockData().getHeight(), Base58.encode(newBlock.getSignature()), blockResult.name()));
+				this.addInvalidBlockSignature(newBlock.getSignature());
+				this.timeInvalidBlockLastReceived = NTP.getTime();
 				return SynchronizationResult.INVALID_DATA;
 			}
 
+			// Block is valid
+			this.timeValidBlockLastReceived = NTP.getTime();
+
 			// Save transactions attached to this block
 			for (Transaction transaction : newBlock.getTransactions()) {
 				TransactionData transactionData = transaction.getTransactionData();
@@ -972,6 +1093,7 @@ public class Synchronizer {
 			Controller.getInstance().onNewBlock(newBlock.getBlockData());
 		}
 
+		this.lastReorgSize = reorgSize;
 		return SynchronizationResult.OK;
 	}
 
@@ -1037,13 +1159,20 @@ public class Synchronizer {
 			for (Transaction transaction : newBlock.getTransactions())
 				transaction.setInitialApprovalStatus();
 
+			newBlock.preProcess();
+
 			ValidationResult blockResult = newBlock.isValid();
 			if (blockResult != ValidationResult.OK) {
 				LOGGER.info(String.format("Peer %s sent invalid block for height %d, sig %.8s: %s", peer,
 						ourHeight, Base58.encode(latestPeerSignature), blockResult.name()));
+				this.addInvalidBlockSignature(newBlock.getSignature());
+				this.timeInvalidBlockLastReceived = NTP.getTime();
 				return SynchronizationResult.INVALID_DATA;
 			}
 
+			// Block is valid
+			this.timeValidBlockLastReceived = NTP.getTime();
+
 			// Save transactions attached to this block
 			for (Transaction transaction : newBlock.getTransactions()) {
 				TransactionData transactionData = transaction.getTransactionData();

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

@@ -0,0 +1,410 @@
+package org.qortal.controller.repository;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.resource.TransactionsResource.ConfirmationStatus;
+import org.qortal.data.naming.NameData;
+import org.qortal.data.transaction.*;
+import org.qortal.naming.Name;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.utils.Unicode;
+
+import java.util.*;
+
+public class NamesDatabaseIntegrityCheck {
+
+    private static final Logger LOGGER = LogManager.getLogger(NamesDatabaseIntegrityCheck.class);
+
+    private static final List<TransactionType> ALL_NAME_TX_TYPE = Arrays.asList(
+            TransactionType.REGISTER_NAME,
+            TransactionType.UPDATE_NAME,
+            TransactionType.BUY_NAME,
+            TransactionType.SELL_NAME
+    );
+
+    private List<TransactionData> nameTransactions = new ArrayList<>();
+
+    public int rebuildName(String name, Repository repository) {
+        int modificationCount = 0;
+        try {
+            List<TransactionData> transactions = this.fetchAllTransactionsInvolvingName(name, repository);
+            if (transactions.isEmpty()) {
+                // This name was never registered, so there's nothing to do
+                return modificationCount;
+            }
+
+            // Loop through each past transaction and re-apply it to the Names table
+            for (TransactionData currentTransaction : transactions) {
+
+                // Process REGISTER_NAME transactions
+                if (currentTransaction.getType() == TransactionType.REGISTER_NAME) {
+                    RegisterNameTransactionData registerNameTransactionData = (RegisterNameTransactionData) currentTransaction;
+                    Name nameObj = new Name(repository, registerNameTransactionData);
+                    nameObj.register();
+                    modificationCount++;
+                    LOGGER.trace("Processed REGISTER_NAME transaction for name {}", name);
+                }
+
+                // Process UPDATE_NAME transactions
+                if (currentTransaction.getType() == TransactionType.UPDATE_NAME) {
+                    UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) currentTransaction;
+
+                    if (Objects.equals(updateNameTransactionData.getNewName(), name) &&
+                            !Objects.equals(updateNameTransactionData.getName(), updateNameTransactionData.getNewName())) {
+                        // This renames an existing name, so we need to process that instead
+                        this.rebuildName(updateNameTransactionData.getName(), repository);
+                    }
+                    else {
+                        Name nameObj = new Name(repository, name);
+                        if (nameObj != null && nameObj.getNameData() != null) {
+                            nameObj.update(updateNameTransactionData);
+                            modificationCount++;
+                            LOGGER.trace("Processed UPDATE_NAME transaction for name {}", name);
+                        } else {
+                            // Something went wrong
+                            throw new DataException(String.format("Name data not found for name %s", updateNameTransactionData.getName()));
+                        }
+                    }
+                }
+
+                // Process SELL_NAME transactions
+                if (currentTransaction.getType() == TransactionType.SELL_NAME) {
+                    SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) currentTransaction;
+                    Name nameObj = new Name(repository, sellNameTransactionData.getName());
+                    if (nameObj != null && nameObj.getNameData() != null) {
+                        nameObj.sell(sellNameTransactionData);
+                        modificationCount++;
+                        LOGGER.trace("Processed SELL_NAME transaction for name {}", name);
+                    }
+                    else {
+                        // Something went wrong
+                        throw new DataException(String.format("Name data not found for name %s", sellNameTransactionData.getName()));
+                    }
+                }
+
+                // Process BUY_NAME transactions
+                if (currentTransaction.getType() == TransactionType.BUY_NAME) {
+                    BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) currentTransaction;
+                    Name nameObj = new Name(repository, buyNameTransactionData.getName());
+                    if (nameObj != null && nameObj.getNameData() != null) {
+                        nameObj.buy(buyNameTransactionData);
+                        modificationCount++;
+                        LOGGER.trace("Processed BUY_NAME transaction for name {}", name);
+                    }
+                    else {
+                        // Something went wrong
+                        throw new DataException(String.format("Name data not found for name %s", buyNameTransactionData.getName()));
+                    }
+                }
+            }
+
+        } catch (DataException e) {
+            LOGGER.info("Unable to run integrity check for name {}: {}", name, e.getMessage());
+        }
+
+        return modificationCount;
+    }
+
+    public int rebuildAllNames() {
+        int modificationCount = 0;
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            List<String> names = this.fetchAllNames(repository);
+            for (String name : names) {
+                modificationCount += this.rebuildName(name, repository);
+            }
+            repository.saveChanges();
+        }
+        catch (DataException e) {
+            LOGGER.info("Error when running integrity check for all names: {}", e.getMessage());
+        }
+
+        //LOGGER.info("modificationCount: {}", modificationCount);
+        return modificationCount;
+    }
+
+    public void runIntegrityCheck() {
+        boolean integrityCheckFailed = false;
+        try (final Repository repository = RepositoryManager.getRepository()) {
+
+            // Fetch all the (confirmed) REGISTER_NAME transactions
+            List<RegisterNameTransactionData> registerNameTransactions = this.fetchRegisterNameTransactions();
+
+            // Loop through each REGISTER_NAME txn signature and request the full transaction data
+            for (RegisterNameTransactionData registerNameTransactionData : registerNameTransactions) {
+                String registeredName = registerNameTransactionData.getName();
+                NameData nameData = repository.getNameRepository().fromName(registeredName);
+
+                // Check to see if this name has been updated or bought at any point
+                TransactionData latestUpdate = this.fetchLatestModificationTransactionInvolvingName(registeredName, repository);
+                if (latestUpdate == null) {
+                    // Name was never updated once registered
+                    // We expect this name to still be registered to this transaction's creator
+
+                    if (nameData == null) {
+                        LOGGER.info("Error: registered name {} doesn't exist in Names table. Adding...", registeredName);
+                        integrityCheckFailed = true;
+                    }
+                    else {
+                        LOGGER.trace("Registered name {} is correctly registered", registeredName);
+                    }
+
+                    // Check the owner is correct
+                    PublicKeyAccount creator = new PublicKeyAccount(repository, registerNameTransactionData.getCreatorPublicKey());
+                    if (!Objects.equals(creator.getAddress(), nameData.getOwner())) {
+                        LOGGER.info("Error: registered name {} is owned by {}, but it should be {}",
+                                registeredName, nameData.getOwner(), creator.getAddress());
+                        integrityCheckFailed = true;
+                    }
+                    else {
+                        LOGGER.trace("Registered name {} has the correct owner", registeredName);
+                    }
+                }
+                else {
+                    // Check if owner is correct after update
+
+                    // Check for name updates
+                    if (latestUpdate.getType() == TransactionType.UPDATE_NAME) {
+                        UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) latestUpdate;
+                        PublicKeyAccount creator = new PublicKeyAccount(repository, updateNameTransactionData.getCreatorPublicKey());
+
+                        // When this name is the "new name", we expect the current owner to match the txn creator
+                        if (Objects.equals(updateNameTransactionData.getNewName(), registeredName)) {
+                            if (!Objects.equals(creator.getAddress(), nameData.getOwner())) {
+                                LOGGER.info("Error: registered name {} is owned by {}, but it should be {}",
+                                        registeredName, nameData.getOwner(), creator.getAddress());
+                                integrityCheckFailed = true;
+                            }
+                            else {
+                                LOGGER.trace("Registered name {} has the correct owner after being updated", registeredName);
+                            }
+                        }
+
+                        // When this name is the old name, we expect the "new name"'s owner to match the txn creator
+                        // The old name will then be unregistered, or re-registered.
+                        // FUTURE: check database integrity for names that have been updated and then the original name re-registered
+                        else if (Objects.equals(updateNameTransactionData.getName(), registeredName)) {
+                            NameData newNameData = repository.getNameRepository().fromName(updateNameTransactionData.getNewName());
+                            if (!Objects.equals(creator.getAddress(), newNameData.getOwner())) {
+                                LOGGER.info("Error: registered name {} is owned by {}, but it should be {}",
+                                        updateNameTransactionData.getNewName(), newNameData.getOwner(), creator.getAddress());
+                                integrityCheckFailed = true;
+                            }
+                            else {
+                                LOGGER.trace("Registered name {} has the correct owner after being updated", updateNameTransactionData.getNewName());
+                            }
+                        }
+
+                        else {
+                            LOGGER.info("Unhandled update case for name {}", registeredName);
+                        }
+                    }
+
+                    // Check for name buys
+                    else if (latestUpdate.getType() == TransactionType.BUY_NAME) {
+                        BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) latestUpdate;
+                        PublicKeyAccount creator = new PublicKeyAccount(repository, buyNameTransactionData.getCreatorPublicKey());
+                        if (!Objects.equals(creator.getAddress(), nameData.getOwner())) {
+                            LOGGER.info("Error: registered name {} is owned by {}, but it should be {}",
+                                    registeredName, nameData.getOwner(), creator.getAddress());
+                            integrityCheckFailed = true;
+                        }
+                        else {
+                            LOGGER.trace("Registered name {} has the correct owner after being bought", registeredName);
+                        }
+                    }
+
+                    // Check for name sells
+                    else if (latestUpdate.getType() == TransactionType.SELL_NAME) {
+                        SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) latestUpdate;
+                        PublicKeyAccount creator = new PublicKeyAccount(repository, sellNameTransactionData.getCreatorPublicKey());
+                        if (!Objects.equals(creator.getAddress(), nameData.getOwner())) {
+                            LOGGER.info("Error: registered name {} is owned by {}, but it should be {}",
+                                    registeredName, nameData.getOwner(), creator.getAddress());
+                            integrityCheckFailed = true;
+                        }
+                        else {
+                            LOGGER.trace("Registered name {} has the correct owner after being listed for sale", registeredName);
+                        }
+                    }
+
+                    else {
+                        LOGGER.info("Unhandled case for name {}", registeredName);
+                    }
+
+                }
+
+            }
+
+        } catch (DataException e) {
+            LOGGER.warn(String.format("Repository issue trying to trim online accounts signatures: %s", e.getMessage()));
+            integrityCheckFailed = true;
+        }
+
+        if (integrityCheckFailed) {
+            LOGGER.info("Registered names database integrity check failed. Bootstrapping is recommended.");
+        } else {
+            LOGGER.info("Registered names database integrity check passed.");
+        }
+    }
+
+    private List<RegisterNameTransactionData> fetchRegisterNameTransactions() {
+        List<RegisterNameTransactionData> registerNameTransactions = new ArrayList<>();
+
+        for (TransactionData transactionData : this.nameTransactions) {
+            if (transactionData.getType() == TransactionType.REGISTER_NAME) {
+                RegisterNameTransactionData registerNameTransactionData = (RegisterNameTransactionData) transactionData;
+                registerNameTransactions.add(registerNameTransactionData);
+            }
+        }
+        return registerNameTransactions;
+    }
+
+    private List<UpdateNameTransactionData> fetchUpdateNameTransactions() {
+        List<UpdateNameTransactionData> updateNameTransactions = new ArrayList<>();
+
+        for (TransactionData transactionData : this.nameTransactions) {
+            if (transactionData.getType() == TransactionType.UPDATE_NAME) {
+                UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) transactionData;
+                updateNameTransactions.add(updateNameTransactionData);
+            }
+        }
+        return updateNameTransactions;
+    }
+
+    private List<SellNameTransactionData> fetchSellNameTransactions() {
+        List<SellNameTransactionData> sellNameTransactions = new ArrayList<>();
+
+        for (TransactionData transactionData : this.nameTransactions) {
+            if (transactionData.getType() == TransactionType.SELL_NAME) {
+                SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) transactionData;
+                sellNameTransactions.add(sellNameTransactionData);
+            }
+        }
+        return sellNameTransactions;
+    }
+
+    private List<BuyNameTransactionData> fetchBuyNameTransactions() {
+        List<BuyNameTransactionData> buyNameTransactions = new ArrayList<>();
+
+        for (TransactionData transactionData : this.nameTransactions) {
+            if (transactionData.getType() == TransactionType.BUY_NAME) {
+                BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) transactionData;
+                buyNameTransactions.add(buyNameTransactionData);
+            }
+        }
+        return buyNameTransactions;
+    }
+
+    private void fetchAllNameTransactions(Repository repository) throws DataException {
+        List<TransactionData> nameTransactions = new ArrayList<>();
+
+        // Fetch all the confirmed REGISTER_NAME transaction signatures
+        List<byte[]> signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(
+                null, null, null, ALL_NAME_TX_TYPE, null, null,
+                ConfirmationStatus.CONFIRMED, null, null, false);
+
+        for (byte[] signature : signatures) {
+            TransactionData transactionData = repository.getTransactionRepository().fromSignature(signature);
+            nameTransactions.add(transactionData);
+        }
+        this.nameTransactions = nameTransactions;
+    }
+
+    private List<TransactionData> fetchAllTransactionsInvolvingName(String name, Repository repository) throws DataException {
+        List<TransactionData> transactions = new ArrayList<>();
+        String reducedName = Unicode.sanitize(name);
+
+        // Fetch all the confirmed name-modification transactions
+        if (this.nameTransactions.isEmpty()) {
+            this.fetchAllNameTransactions(repository);
+        }
+
+        for (TransactionData transactionData : this.nameTransactions) {
+
+            if ((transactionData instanceof RegisterNameTransactionData)) {
+                RegisterNameTransactionData registerNameTransactionData = (RegisterNameTransactionData) transactionData;
+                if (Objects.equals(registerNameTransactionData.getReducedName(), reducedName)) {
+                    transactions.add(transactionData);
+                }
+            }
+            if ((transactionData instanceof UpdateNameTransactionData)) {
+                UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) transactionData;
+                if (Objects.equals(updateNameTransactionData.getName(), name) ||
+                        Objects.equals(updateNameTransactionData.getReducedNewName(), reducedName)) {
+                    transactions.add(transactionData);
+                }
+            }
+            if ((transactionData instanceof BuyNameTransactionData)) {
+                BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) transactionData;
+                if (Objects.equals(buyNameTransactionData.getName(), name)) {
+                    transactions.add(transactionData);
+                }
+            }
+            if ((transactionData instanceof SellNameTransactionData)) {
+                SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) transactionData;
+                if (Objects.equals(sellNameTransactionData.getName(), name)) {
+                    transactions.add(transactionData);
+                }
+            }
+        }
+        return transactions;
+    }
+
+    private TransactionData fetchLatestModificationTransactionInvolvingName(String registeredName, Repository repository) throws DataException {
+        List<TransactionData> transactionsInvolvingName = this.fetchAllTransactionsInvolvingName(registeredName, repository);
+
+        // Get the latest update for this name (excluding REGISTER_NAME transactions)
+        TransactionData latestUpdateToName = transactionsInvolvingName.stream()
+                .filter(txn -> txn.getType() != TransactionType.REGISTER_NAME)
+                .max(Comparator.comparing(TransactionData::getTimestamp))
+                .orElse(null);
+
+        return latestUpdateToName;
+    }
+
+    private List<String> fetchAllNames(Repository repository) throws DataException {
+        List<String> names = new ArrayList<>();
+
+        // Fetch all the confirmed name transactions
+        if (this.nameTransactions.isEmpty()) {
+            this.fetchAllNameTransactions(repository);
+        }
+
+        for (TransactionData transactionData : this.nameTransactions) {
+
+            if ((transactionData instanceof RegisterNameTransactionData)) {
+                RegisterNameTransactionData registerNameTransactionData = (RegisterNameTransactionData) transactionData;
+                if (!names.contains(registerNameTransactionData.getName())) {
+                    names.add(registerNameTransactionData.getName());
+                }
+            }
+            if ((transactionData instanceof UpdateNameTransactionData)) {
+                UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) transactionData;
+                if (!names.contains(updateNameTransactionData.getName())) {
+                    names.add(updateNameTransactionData.getName());
+                }
+                if (!names.contains(updateNameTransactionData.getNewName())) {
+                    names.add(updateNameTransactionData.getNewName());
+                }
+            }
+            if ((transactionData instanceof BuyNameTransactionData)) {
+                BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) transactionData;
+                if (!names.contains(buyNameTransactionData.getName())) {
+                    names.add(buyNameTransactionData.getName());
+                }
+            }
+            if ((transactionData instanceof SellNameTransactionData)) {
+                SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) transactionData;
+                if (!names.contains(sellNameTransactionData.getName())) {
+                    names.add(sellNameTransactionData.getName());
+                }
+            }
+        }
+        return names;
+    }
+
+}

src/main/java/org/qortal/controller/tradebot/BitcoinACCTv1TradeBot.java

@@ -360,6 +360,7 @@ public class BitcoinACCTv1TradeBot implements AcctTradeBot {
 			case BOB_DONE:
 			case ALICE_REFUNDED:
 			case BOB_REFUNDED:
+			case ALICE_REFUNDING_A:
 				return true;
 
 			default:
@@ -383,15 +384,6 @@ public class BitcoinACCTv1TradeBot implements AcctTradeBot {
 			atData = repository.getATRepository().fromATAddress(tradeBotData.getAtAddress());
 			if (atData == null) {
 				LOGGER.debug(() -> String.format("Unable to fetch trade AT %s from repository", tradeBotData.getAtAddress()));
-
-				// If it has been over 24 hours since we last updated this trade-bot entry then assume AT is never coming back
-				// and so wipe the trade-bot entry
-				if (tradeBotData.getTimestamp() + MAX_AT_CONFIRMATION_PERIOD < NTP.getTime()) {
-					LOGGER.info(() -> String.format("AT %s has been gone for too long - deleting trade-bot entry", tradeBotData.getAtAddress()));
-					repository.getCrossChainRepository().delete(tradeBotData.getTradePrivateKey());
-					repository.saveChanges();
-				}
-
 				return;
 			}
 
@@ -1042,7 +1034,7 @@ public class BitcoinACCTv1TradeBot implements AcctTradeBot {
 			return;
 		}
 
-		byte[] secretA = BitcoinACCTv1.findSecretA(repository, crossChainTradeData);
+		byte[] secretA = BitcoinACCTv1.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;

src/main/java/org/qortal/controller/tradebot/DogecoinACCTv1TradeBot.java

@@ -0,0 +1,884 @@
+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 DogecoinACCTv1TradeBot implements AcctTradeBot {
+
+	private static final Logger LOGGER = LogManager.getLogger(DogecoinACCTv1TradeBot.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 DogecoinACCTv1TradeBot 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 DogecoinACCTv1TradeBot() {
+	}
+
+	public static synchronized DogecoinACCTv1TradeBot getInstance() {
+		if (instance == null)
+			instance = new DogecoinACCTv1TradeBot();
+
+		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 DOGE.
+	 * <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 Dogecoin) 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'/Dogecoin public key hash - used by Alice's P2SH scripts to allow redeem</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>DOGE 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 Dogecoin receiving address into public key hash (we only support P2PKH at this time)
+		Address dogecoinReceivingAddress;
+		try {
+			dogecoinReceivingAddress = Address.fromString(Dogecoin.getInstance().getNetworkParameters(), tradeBotCreateRequest.receivingAddress);
+		} catch (AddressFormatException e) {
+			throw new DataException("Unsupported Dogecoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+		}
+		if (dogecoinReceivingAddress.getOutputScriptType() != ScriptType.P2PKH)
+			throw new DataException("Unsupported Dogecoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+
+		byte[] dogecoinReceivingAccountInfo = dogecoinReceivingAddress.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/DOGE ACCT";
+		String description = "QORT/DOGE cross-chain trade";
+		String aTType = "ACCT";
+		String tags = "ACCT QORT DOGE";
+		byte[] creationBytes = DogecoinACCTv1.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, DogecoinACCTv1.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.DOGECOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				tradeBotCreateRequest.foreignAmount, null, null, null, dogecoinReceivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Built AT %s. Waiting for deployment", atAddress));
+
+		// Attempt to backup the trade bot data
+		TradeBot.backupTradeBotData(repository);
+
+		// 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 DOGE to an existing offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a Dogecoin 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 Dogecoin 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 Dogecoin main-net)
+	 * or 'tprv' for (Dogecoin 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 Dogecoin amount expected by 'Bob'.
+	 * <p>
+	 * If the Dogecoin 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 Dogecoin 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, DogecoinACCTv1.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.DOGECOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				crossChainTradeData.expectedForeignAmount, xprv58, null, lockTimeA, receivingPublicKeyHash);
+
+		// Attempt to backup the trade bot data
+		TradeBot.backupTradeBotData(repository);
+
+		// Check we have enough funds via xprv58 to fund P2SH to cover expectedForeignAmount
+		long p2shFee;
+		try {
+			p2shFee = Dogecoin.getInstance().getP2shFee(now);
+		} catch (ForeignBlockchainException e) {
+			LOGGER.debug("Couldn't estimate Dogecoin 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 = Dogecoin.getInstance().deriveP2shAddress(redeemScriptBytes);
+
+		// Build transaction for funding P2SH-A
+		Transaction p2shFundingTransaction = Dogecoin.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 {
+			Dogecoin.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 = DogecoinACCTv1.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 = DogecoinACCTv1.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 Dogecoin 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;
+		}
+
+		Dogecoin dogecoin = Dogecoin.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 Dogecoin pubkeyhash and lockTime-A
+			byte[] messageData = messageTransactionData.getData();
+			DogecoinACCTv1.OfferMessageData offerMessageData = DogecoinACCTv1.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				continue;
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerDogecoinPKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+			long messageTimestamp = messageTransactionData.getTimestamp();
+			int refundTimeout = DogecoinACCTv1.calcRefundTimeout(messageTimestamp, lockTimeA);
+
+			// Determine P2SH-A address and confirm funded
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(aliceForeignPublicKeyHash, lockTimeA, tradeBotData.getTradeForeignPublicKeyHash(), hashOfSecretA);
+			String p2shAddressA = dogecoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Dogecoin.getInstance().getP2shFee(feeTimestamp);
+			final long minimumAmountA = tradeBotData.getForeignAmount() + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(dogecoin.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 = DogecoinACCTv1.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 DOGE 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;
+
+		Dogecoin dogecoin = Dogecoin.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 = dogecoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Dogecoin.getInstance().getP2shFee(feeTimestamp);
+			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(dogecoin.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 = DogecoinACCTv1.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 = DogecoinACCTv1.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 DOGE 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 DOGE funds from P2SH-A
+	 * to Bob's 'foreign'/Dogecoin trade legacy-format address, as derived from trade private key.
+	 * <p>
+	 * (This could potentially be 'improved' to send DOGE 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 DOGE
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
+
+			return;
+		}
+
+		byte[] secretA = DogecoinACCTv1.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
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		byte[] receivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+		int lockTimeA = crossChainTradeData.lockTimeA;
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTimeA, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
+		String p2shAddressA = dogecoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Dogecoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(dogecoin.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 = dogecoin.getUnspentOutputs(p2shAddressA);
+
+				Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(dogecoin.getNetworkParameters(), redeemAmount, redeemKey,
+						fundingOutputs, redeemScriptA, secretA, receivingAccountInfo);
+
+				dogecoin.broadcastTransaction(p2shRedeemTransaction);
+				break;
+			}
+		}
+
+		String receivingAddress = dogecoin.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;
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+		int medianBlockTime = dogecoin.getMedianBlockTime();
+		if (medianBlockTime <= lockTimeA)
+			return;
+
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+		String p2shAddressA = dogecoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Dogecoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(dogecoin.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 = dogecoin.getUnspentOutputs(p2shAddressA);
+
+				// Determine receive address for refund
+				String receiveAddress = dogecoin.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+				Address receiving = Address.fromString(dogecoin.getNetworkParameters(), receiveAddress);
+
+				Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(dogecoin.getNetworkParameters(), refundAmount, refundKey,
+						fundingOutputs, redeemScriptA, lockTimeA, receiving.getHash());
+
+				dogecoin.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/LitecoinACCTv1TradeBot.java

@@ -364,6 +364,7 @@ public class LitecoinACCTv1TradeBot implements AcctTradeBot {
 			case BOB_DONE:
 			case ALICE_REFUNDED:
 			case BOB_REFUNDED:
+			case ALICE_REFUNDING_A:
 				return true;
 
 			default:
@@ -387,15 +388,6 @@ public class LitecoinACCTv1TradeBot implements AcctTradeBot {
 			atData = repository.getATRepository().fromATAddress(tradeBotData.getAtAddress());
 			if (atData == null) {
 				LOGGER.debug(() -> String.format("Unable to fetch trade AT %s from repository", tradeBotData.getAtAddress()));
-
-				// If it has been over 24 hours since we last updated this trade-bot entry then assume AT is never coming back
-				// and so wipe the trade-bot entry
-				if (tradeBotData.getTimestamp() + MAX_AT_CONFIRMATION_PERIOD < NTP.getTime()) {
-					LOGGER.info(() -> String.format("AT %s has been gone for too long - deleting trade-bot entry", tradeBotData.getAtAddress()));
-					repository.getCrossChainRepository().delete(tradeBotData.getTradePrivateKey());
-					repository.saveChanges();
-				}
-
 				return;
 			}
 
@@ -725,16 +717,16 @@ public class LitecoinACCTv1TradeBot implements AcctTradeBot {
 			// Not finished yet
 			return;
 
-		// If AT is not REDEEMED then something has gone wrong
-		if (crossChainTradeData.mode != AcctMode.REDEEMED) {
-			// Not redeemed so must be refunded/cancelled
+		// 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 LTC
 			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
 					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
 
 			return;
 		}
 
-		byte[] secretA = LitecoinACCTv1.findSecretA(repository, crossChainTradeData);
+		byte[] secretA = LitecoinACCTv1.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;

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

@@ -17,11 +17,7 @@ import org.qortal.account.PrivateKeyAccount;
 import org.qortal.api.model.crosschain.TradeBotCreateRequest;
 import org.qortal.controller.Controller;
 import org.qortal.controller.tradebot.AcctTradeBot.ResponseResult;
-import org.qortal.crosschain.ACCT;
-import org.qortal.crosschain.BitcoinACCTv1;
-import org.qortal.crosschain.ForeignBlockchainException;
-import org.qortal.crosschain.LitecoinACCTv1;
-import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.*;
 import org.qortal.data.at.ATData;
 import org.qortal.data.crosschain.CrossChainTradeData;
 import org.qortal.data.crosschain.TradeBotData;
@@ -80,6 +76,7 @@ public class TradeBot implements Listener {
 	static {
 		acctTradeBotSuppliers.put(BitcoinACCTv1.class, BitcoinACCTv1TradeBot::getInstance);
 		acctTradeBotSuppliers.put(LitecoinACCTv1.class, LitecoinACCTv1TradeBot::getInstance);
+		acctTradeBotSuppliers.put(DogecoinACCTv1.class, DogecoinACCTv1TradeBot::getInstance);
 	}
 
 	private static TradeBot instance;

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

@@ -20,4 +20,6 @@ public interface ACCT {
 
 	public byte[] buildCancelMessage(String creatorQortalAddress);
 
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException;
+
 }

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

@@ -67,7 +67,11 @@ public class Bitcoin extends Bitcoiny {
 						new Server("192.166.219.200", Server.ConnectionType.SSL, 50002),
 						new Server("2ex.digitaleveryware.com", Server.ConnectionType.SSL, 50002),
 						new Server("dxm.no-ip.biz", Server.ConnectionType.SSL, 50002),
-						new Server("caleb.vegas", Server.ConnectionType.SSL, 50002));
+						new Server("caleb.vegas", Server.ConnectionType.SSL, 50002),
+						new Server("ecdsa.net", Server.ConnectionType.SSL, 110),
+						new Server("electrum.hsmiths.com", Server.ConnectionType.SSL, 995),
+						new Server("elec.luggs.co", Server.ConnectionType.SSL, 443),
+						new Server("btc.smsys.me", Server.ConnectionType.SSL, 995));
 			}
 
 			@Override

src/main/java/org/qortal/crosschain/BitcoinACCTv1.java

@@ -872,7 +872,8 @@ public class BitcoinACCTv1 implements ACCT {
 		return (int) ((lockTimeA + (offerMessageTimestamp / 1000L)) / 2L);
 	}
 
-	public static byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+	@Override
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
 		String atAddress = crossChainTradeData.qortalAtAddress;
 		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
 

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

@@ -169,6 +169,11 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 		return this.bitcoinjContext.getFeePerKb();
 	}
 
+	/** Returns minimum order size in sats. To be overridden for coins that need to restrict order size. */
+	public long getMinimumOrderAmount() {
+		return 0L;
+	}
+
 	/**
 	 * Returns fixed P2SH spending fee, in sats per 1000bytes, optionally for historic timestamp.
 	 *
@@ -346,6 +351,10 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 		Set<BitcoinyTransaction> walletTransactions = new HashSet<>();
 		Set<String> keySet = new HashSet<>();
 
+		// Set the number of consecutive empty batches required before giving up
+		final int numberOfAdditionalBatchesToSearch = 5;
+
+		int unusedCounter = 0;
 		int ki = 0;
 		do {
 			boolean areAllKeysUnused = true;
@@ -369,9 +378,19 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 				}
 			}
 
-			if (areAllKeysUnused)
-				// No transactions for this batch of keys so assume we're done searching.
-				break;
+			if (areAllKeysUnused) {
+				// No transactions
+				if (unusedCounter >= numberOfAdditionalBatchesToSearch) {
+					// ... and we've hit our search limit
+					break;
+				}
+				// We haven't hit our search limit yet so increment the counter and keep looking
+				unusedCounter++;
+			}
+			else {
+				// Some keys in this batch were used, so reset the counter
+				unusedCounter = 0;
+			}
 
 			// Generate some more keys
 			keys.addAll(generateMoreKeys(keyChain));
@@ -387,14 +406,24 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 	protected SimpleTransaction convertToSimpleTransaction(BitcoinyTransaction t, Set<String> keySet) {
 		long amount = 0;
 		long total = 0L;
+		long totalInputAmount = 0L;
+		long totalOutputAmount = 0L;
+		List<SimpleTransaction.Input> inputs = new ArrayList<>();
+		List<SimpleTransaction.Output> outputs = new ArrayList<>();
+
 		for (BitcoinyTransaction.Input input : t.inputs) {
 			try {
 				BitcoinyTransaction t2 = getTransaction(input.outputTxHash);
 				List<String> senders = t2.outputs.get(input.outputVout).addresses;
+				long inputAmount = t2.outputs.get(input.outputVout).value;
+				totalInputAmount += inputAmount;
 				for (String sender : senders) {
+					boolean addressInWallet = false;
 					if (keySet.contains(sender)) {
-						total += t2.outputs.get(input.outputVout).value;
+						total += inputAmount;
+						addressInWallet = true;
 					}
+					inputs.add(new SimpleTransaction.Input(sender, inputAmount, addressInWallet));
 				}
 			} catch (ForeignBlockchainException e) {
 				LOGGER.trace("Failed to retrieve transaction information {}", input.outputTxHash);
@@ -403,17 +432,22 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 		if (t.outputs != null && !t.outputs.isEmpty()) {
 			for (BitcoinyTransaction.Output output : t.outputs) {
 				for (String address : output.addresses) {
+					boolean addressInWallet = false;
 					if (keySet.contains(address)) {
 						if (total > 0L) {
 							amount -= (total - output.value);
 						} else {
 							amount += output.value;
 						}
+						addressInWallet = true;
 					}
+					outputs.add(new SimpleTransaction.Output(address, output.value, addressInWallet));
 				}
+				totalOutputAmount += output.value;
 			}
 		}
-		return new SimpleTransaction(t.txHash, t.timestamp, amount);
+		long fee = totalInputAmount - totalOutputAmount;
+		return new SimpleTransaction(t.txHash, t.timestamp, amount, fee, inputs, outputs);
 	}
 
 	/**

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

@@ -0,0 +1,171 @@
+package org.qortal.crosschain;
+
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.libdohj.params.DogecoinMainNetParams;
+//import org.libdohj.params.DogecoinRegTestParams;
+import org.libdohj.params.DogecoinTestNet3Params;
+import org.qortal.crosschain.ElectrumX.Server;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
+import org.qortal.settings.Settings;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.Map;
+
+public class Dogecoin extends Bitcoiny {
+
+	public static final String CURRENCY_CODE = "DOGE";
+
+	private static final Coin DEFAULT_FEE_PER_KB = Coin.valueOf(500000000); // 5 DOGE per 1000 bytes
+
+	private static final long MINIMUM_ORDER_AMOUNT = 300000000L; // 3 DOGE minimum order. The RPC dust threshold is around 2 DOGE
+
+	// Temporary values until a dynamic fee system is written.
+	private static final long MAINNET_FEE = 110000000L;
+	private static final long NON_MAINNET_FEE = 10000L; // TODO: calibrate this
+
+	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 DogecoinNet {
+		MAIN {
+			@Override
+			public NetworkParameters getParams() {
+				return DogecoinMainNetParams.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(
+						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						new Server("electrum1.cipig.net", ConnectionType.TCP, 10060),
+						new Server("electrum2.cipig.net", ConnectionType.TCP, 10060),
+						new Server("electrum3.cipig.net", ConnectionType.TCP, 10060));
+						// TODO: add more mainnet servers. It's too centralized.
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "1a91e3dace36e2be3bf030a65679fe821aa1d6ef92e7c9902eb318182c355691";
+			}
+
+			@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 DogecoinTestNet3Params.get();
+			}
+
+			@Override
+			public Collection<Server> getServers() {
+				return Arrays.asList(); // TODO: find testnet servers
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "4966625a4b2851d9fdee139e56211a0d88575f59ed816ff5e6a63deb4e3e29a0";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		},
+		REGTEST {
+			@Override
+			public NetworkParameters getParams() {
+				return null; // TODO: DogecoinRegTestParams.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 Dogecoin instance;
+
+	private final DogecoinNet dogecoinNet;
+
+	// Constructors and instance
+
+	private Dogecoin(DogecoinNet dogecoinNet, BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		super(blockchain, bitcoinjContext, currencyCode);
+		this.dogecoinNet = dogecoinNet;
+
+		LOGGER.info(() -> String.format("Starting Dogecoin support using %s", this.dogecoinNet.name()));
+	}
+
+	public static synchronized Dogecoin getInstance() {
+		if (instance == null) {
+			DogecoinNet dogecoinNet = Settings.getInstance().getDogecoinNet();
+
+			BitcoinyBlockchainProvider electrumX = new ElectrumX("Dogecoin-" + dogecoinNet.name(), dogecoinNet.getGenesisHash(), dogecoinNet.getServers(), DEFAULT_ELECTRUMX_PORTS);
+			Context bitcoinjContext = new Context(dogecoinNet.getParams());
+
+			instance = new Dogecoin(dogecoinNet, 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 DOGE 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.dogecoinNet.getP2shFee(timestamp);
+	}
+
+}

src/main/java/org/qortal/crosschain/DogecoinACCTv1.java

@@ -0,0 +1,855 @@
+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 Dogecoin & 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 Dogecoin & Qortal 'trade' keys</li>
+ * 			<li>Alice funds Dogecoin 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' Dogecoin 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 Dogecoin 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 Dogecoin trade key and secret-A</li>
+ * 			<li>P2SH-A DOGE funds end up at Dogecoin address determined by redeem transaction output(s)</li>
+ * 		</ul>
+ * </li>
+ * </ul>
+ */
+public class DogecoinACCTv1 implements ACCT {
+
+	private static final Logger LOGGER = LogManager.getLogger(DogecoinACCTv1.class);
+
+	public static final String NAME = DogecoinACCTv1.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("0eb49b0313ff3855a29d860c2a8203faa2ef62e28ea30459321f176079cfa3a5").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[] partnerDogecoinPKH;
+		public byte[] hashOfSecretA;
+		public long lockTimeA;
+	}
+	public static final int OFFER_MESSAGE_LENGTH = 20 /*partnerDogecoinPKH*/ + 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 Dogecoin 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 DogecoinACCTv1 instance;
+
+	private DogecoinACCTv1() {
+	}
+
+	public static synchronized DogecoinACCTv1 getInstance() {
+		if (instance == null)
+			instance = new DogecoinACCTv1();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Dogecoin.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 dogecoinPublicKeyHash 20-byte HASH160 of creator's trade Dogecoin public key
+	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
+	 * @param dogecoinAmount how much DOGE the AT creator is expecting to trade
+	 * @param tradeTimeout suggested timeout for entire trade
+	 */
+	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] dogecoinPublicKeyHash, long qortAmount, long dogecoinAmount, int tradeTimeout) {
+		if (dogecoinPublicKeyHash.length != 20)
+			throw new IllegalArgumentException("Dogecoin 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 addrDogecoinPublicKeyHash = addrCounter;
+		addrCounter += 4;
+
+		final int addrQortAmount = addrCounter++;
+		final int addrDogecoinAmount = 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 addrTradeMessagePartnerDogecoinPKHOffset = addrCounter++;
+		final int addrPartnerDogecoinPKHPointer = 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 addrPartnerDogecoinPKH = 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));
+
+		// Dogecoin public key hash
+		assert dataByteBuffer.position() == addrDogecoinPublicKeyHash * MachineState.VALUE_SIZE : "addrDogecoinPublicKeyHash incorrect";
+		dataByteBuffer.put(Bytes.ensureCapacity(dogecoinPublicKeyHash, 32, 0));
+
+		// Redeem Qort amount
+		assert dataByteBuffer.position() == addrQortAmount * MachineState.VALUE_SIZE : "addrQortAmount incorrect";
+		dataByteBuffer.putLong(qortAmount);
+
+		// Expected Dogecoin amount
+		assert dataByteBuffer.position() == addrDogecoinAmount * MachineState.VALUE_SIZE : "addrDogecoinAmount incorrect";
+		dataByteBuffer.putLong(dogecoinAmount);
+
+		// 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 Dogecoin PKH
+		assert dataByteBuffer.position() == addrTradeMessagePartnerDogecoinPKHOffset * MachineState.VALUE_SIZE : "addrTradeMessagePartnerDogecoinPKHOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Index into data segment of partner's Dogecoin PKH, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerDogecoinPKHPointer * MachineState.VALUE_SIZE : "addrPartnerDogecoinPKHPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerDogecoinPKH);
+
+		// 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 */
+
+				/* NOP - to ensure DOGECOIN ACCT is unique */
+				codeByteBuffer.put(OpCode.NOP.compile());
+
+				// 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));
+
+				// 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();
+
+				// 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 Dogecoin 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, addrTradeMessagePartnerDogecoinPKHOffset));
+				// Store partner's Dogecoin PKH (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerDogecoinPKHPointer));
+				// 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 DOGE-QORT ACCT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		assert Arrays.equals(Crypto.digest(codeBytes), DogecoinACCTv1.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.DOGECOIN.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 Dogecoin/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 DOGE 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 Dogecoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Dogecoin 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 Dogecoin PKH
+		byte[] partnerDogecoinPKH = new byte[20];
+		dataByteBuffer.get(partnerDogecoinPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerDogecoinPKH.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 = partnerDogecoinPKH;
+			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.partnerDogecoinPKH = 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/ElectrumX.java

@@ -33,6 +33,7 @@ import org.qortal.crypto.TrustlessSSLSocketFactory;
 
 import com.google.common.hash.HashCode;
 import com.google.common.primitives.Bytes;
+import org.qortal.utils.BitTwiddling;
 
 /** ElectrumX network support for querying Bitcoiny-related info like block headers, transaction outputs, etc. */
 public class ElectrumX extends BitcoinyBlockchainProvider {
@@ -171,13 +172,41 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 		Long returnedCount = (Long) countObj;
 		String hex = (String) hexObj;
 
-		byte[] raw = HashCode.fromString(hex).asBytes();
-		if (raw.length != returnedCount * BLOCK_HEADER_LENGTH)
-			throw new ForeignBlockchainException.NetworkException("Unexpected raw header length in JSON from ElectrumX blockchain.block.headers RPC");
-
 		List<byte[]> rawBlockHeaders = new ArrayList<>(returnedCount.intValue());
-		for (int i = 0; i < returnedCount; ++i)
-			rawBlockHeaders.add(Arrays.copyOfRange(raw, i * BLOCK_HEADER_LENGTH, (i + 1) * BLOCK_HEADER_LENGTH));
+
+		byte[] raw = HashCode.fromString(hex).asBytes();
+
+		// Most chains use a fixed length 80 byte header, so block headers can be split up by dividing the hex into
+		// 80-byte segments. However, some chains such as DOGE use variable length headers due to AuxPoW or other
+		// reasons. In these cases we can identify the start of each block header by the location of the block version
+		// numbers. Each block starts with a version number, and for DOGE this is easily identifiable (6422788) at the
+		// time of writing (Jul 2021). If we encounter a chain that is using more generic version numbers (e.g. 1)
+		// and can't be used to accurately identify block indexes, then there are sufficient checks to ensure an
+		// exception is thrown.
+
+		if (raw.length == returnedCount * BLOCK_HEADER_LENGTH) {
+			// Fixed-length header (BTC, LTC, etc)
+			for (int i = 0; i < returnedCount; ++i) {
+				rawBlockHeaders.add(Arrays.copyOfRange(raw, i * BLOCK_HEADER_LENGTH, (i + 1) * BLOCK_HEADER_LENGTH));
+			}
+		}
+		else if (raw.length > returnedCount * BLOCK_HEADER_LENGTH) {
+			// Assume AuxPoW variable length header (DOGE)
+			int referenceVersion = BitTwiddling.intFromLEBytes(raw, 0); // DOGE uses 6422788 at time of commit (Jul 2021)
+			for (int i = 0; i < raw.length - 4; ++i) {
+				// Locate the start of each block by its version number
+				if (BitTwiddling.intFromLEBytes(raw, i) == referenceVersion) {
+					rawBlockHeaders.add(Arrays.copyOfRange(raw, i, i + BLOCK_HEADER_LENGTH));
+				}
+			}
+			// Ensure that we found the correct number of block headers
+			if (rawBlockHeaders.size() != count) {
+				throw new ForeignBlockchainException.NetworkException("Unexpected raw header contents in JSON from ElectrumX blockchain.block.headers RPC.");
+			}
+		}
+		else if (raw.length != returnedCount * BLOCK_HEADER_LENGTH) {
+			throw new ForeignBlockchainException.NetworkException("Unexpected raw header length in JSON from ElectrumX blockchain.block.headers RPC");
+		}
 
 		return rawBlockHeaders;
 	}
@@ -518,6 +547,7 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 			}
 
 			// Failed to perform RPC - maybe lack of servers?
+			LOGGER.info("Error: No connected Electrum servers when trying to make RPC call");
 			throw new ForeignBlockchainException.NetworkException(String.format("Failed to perform ElectrumX RPC %s", method));
 		}
 	}
@@ -623,18 +653,27 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 
 		Object errorObj = responseJson.get("error");
 		if (errorObj != null) {
-			if (errorObj instanceof String)
-				throw new ForeignBlockchainException.NetworkException(String.format("Unexpected error message from ElectrumX RPC %s: %s", method, (String) errorObj), this.currentServer);
+			if (errorObj instanceof String) {
+				LOGGER.debug(String.format("Unexpected error message from ElectrumX server %s for RPC method %s: %s", this.currentServer, method, (String) errorObj));
+				// Try another server
+				return null;
+			}
 
-			if (!(errorObj instanceof JSONObject))
-				throw new ForeignBlockchainException.NetworkException(String.format("Unexpected error response from ElectrumX RPC %s", method), this.currentServer);
+			if (!(errorObj instanceof JSONObject)) {
+				LOGGER.debug(String.format("Unexpected error response from ElectrumX server %s for RPC method %s", this.currentServer, method));
+				// Try another server
+				return null;
+			}
 
 			JSONObject errorJson = (JSONObject) errorObj;
 
 			Object messageObj = errorJson.get("message");
 
-			if (!(messageObj instanceof String))
-				throw new ForeignBlockchainException.NetworkException(String.format("Missing/invalid message in error response from ElectrumX RPC %s", method), this.currentServer);
+			if (!(messageObj instanceof String)) {
+				LOGGER.debug(String.format("Missing/invalid message in error response from ElectrumX server %s for RPC method %s", this.currentServer, method));
+				// Try another server
+				return null;
+			}
 
 			String message = (String) messageObj;
 

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

@@ -6,4 +6,6 @@ public interface ForeignBlockchain {
 
 	public boolean isValidWalletKey(String walletKey);
 
+	public long getMinimumOrderAmount();
+
 }

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

@@ -21,6 +21,8 @@ public class Litecoin extends Bitcoiny {
 
 	private static final Coin DEFAULT_FEE_PER_KB = Coin.valueOf(10000); // 0.0001 LTC per 1000 bytes
 
+	private static final long MINIMUM_ORDER_AMOUNT = 1000000; // 0.01 LTC minimum order, to avoid dust errors
+
 	// Temporary values until a dynamic fee system is written.
 	private static final long MAINNET_FEE = 1000L;
 	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
@@ -51,7 +53,10 @@ public class Litecoin extends Bitcoiny {
 						new Server("ltc.rentonisk.com", Server.ConnectionType.TCP, 50001),
 						new Server("ltc.rentonisk.com", Server.ConnectionType.SSL, 50002),
 						new Server("electrum-ltc.petrkr.net", Server.ConnectionType.SSL, 60002),
-						new Server("ltc.litepay.ch", Server.ConnectionType.SSL, 50022));
+						new Server("ltc.litepay.ch", Server.ConnectionType.SSL, 50022),
+						new Server("electrum-ltc-bysh.me", Server.ConnectionType.TCP, 50002),
+						new Server("electrum.jochen-hoenicke.de", Server.ConnectionType.TCP, 50005),
+						new Server("node.ispol.sk", Server.ConnectionType.TCP, 50004));
 			}
 
 			@Override
@@ -161,6 +166,11 @@ public class Litecoin extends Bitcoiny {
 		return DEFAULT_FEE_PER_KB;
 	}
 
+	@Override
+	public long getMinimumOrderAmount() {
+		return MINIMUM_ORDER_AMOUNT;
+	}
+
 	/**
 	 * Returns estimated LTC fee, in sats per 1000bytes, optionally for historic timestamp.
 	 * 

src/main/java/org/qortal/crosschain/LitecoinACCTv1.java

@@ -810,7 +810,8 @@ public class LitecoinACCTv1 implements ACCT {
 		return (int) ((lockTimeA - (offerMessageTimestamp / 1000L)) / 2L / 60L);
 	}
 
-	public static byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+	@Override
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
 		String atAddress = crossChainTradeData.qortalAtAddress;
 		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
 

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

@@ -2,20 +2,85 @@ package org.qortal.crosschain;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
+import java.util.List;
 
 @XmlAccessorType(XmlAccessType.FIELD)
 public class SimpleTransaction {
     private String txHash;
     private Integer timestamp;
     private long totalAmount;
+    private long feeAmount;
+    private List<Input> inputs;
+    private List<Output> outputs;
+
+
+    @XmlAccessorType(XmlAccessType.FIELD)
+    public static class Input {
+        private String address;
+        private long amount;
+        private boolean addressInWallet;
+
+        public Input() {
+        }
+
+        public Input(String address, long amount, boolean addressInWallet) {
+            this.address = address;
+            this.amount = amount;
+            this.addressInWallet = addressInWallet;
+        }
+
+        public String getAddress() {
+            return address;
+        }
+
+        public long getAmount() {
+            return amount;
+        }
+
+        public boolean getAddressInWallet() {
+            return addressInWallet;
+        }
+    }
+
+    @XmlAccessorType(XmlAccessType.FIELD)
+    public static class Output {
+        private String address;
+        private long amount;
+        private boolean addressInWallet;
+
+        public Output() {
+        }
+
+        public Output(String address, long amount, boolean addressInWallet) {
+            this.address = address;
+            this.amount = amount;
+            this.addressInWallet = addressInWallet;
+        }
+
+        public String getAddress() {
+            return address;
+        }
+
+        public long getAmount() {
+            return amount;
+        }
+
+        public boolean getAddressInWallet() {
+            return addressInWallet;
+        }
+    }
+
 
     public SimpleTransaction() {
     }
 
-    public SimpleTransaction(String txHash, Integer timestamp, long totalAmount) {
+    public SimpleTransaction(String txHash, Integer timestamp, long totalAmount, long feeAmount, List<Input> inputs, List<Output> outputs) {
         this.txHash = txHash;
         this.timestamp = timestamp;
         this.totalAmount = totalAmount;
+        this.feeAmount = feeAmount;
+        this.inputs = inputs;
+        this.outputs = outputs;
     }
 
     public String getTxHash() {
@@ -29,4 +94,16 @@ public class SimpleTransaction {
     public long getTotalAmount() {
         return totalAmount;
     }
-}
+
+    public long getFeeAmount() {
+        return feeAmount;
+    }
+
+    public List<Input> getInputs() {
+        return this.inputs;
+    }
+
+    public List<Output> getOutputs() {
+        return this.outputs;
+    }
+}

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

@@ -39,6 +39,20 @@ public enum SupportedBlockchain {
 		public ACCT getLatestAcct() {
 			return LitecoinACCTv1.getInstance();
 		}
+	},
+
+	DOGECOIN(Arrays.asList(
+			Triple.valueOf(DogecoinACCTv1.NAME, DogecoinACCTv1.CODE_BYTES_HASH, DogecoinACCTv1::getInstance)
+		)) {
+		@Override
+		public ForeignBlockchain getInstance() {
+			return Dogecoin.getInstance();
+		}
+
+		@Override
+		public ACCT getLatestAcct() {
+			return DogecoinACCTv1.getInstance();
+		}
 	};
 
 	private static final Map<ByteArray, Supplier<ACCT>> supportedAcctsByCodeHash = Arrays.stream(SupportedBlockchain.values())
@@ -110,4 +124,4 @@ public enum SupportedBlockchain {
 		return acctInstanceSupplier.get();
 	}
 
-}
+}

src/main/java/org/qortal/data/at/ATData.java

@@ -23,6 +23,7 @@ public class ATData {
 	private boolean isFrozen;
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private Long frozenBalance;
+	private Long sleepUntilMessageTimestamp;
 
 	// Constructors
 
@@ -31,7 +32,8 @@ public class ATData {
 	}
 
 	public ATData(String ATAddress, byte[] creatorPublicKey, long creation, int version, long assetId, byte[] codeBytes, byte[] codeHash,
-			boolean isSleeping, Integer sleepUntilHeight, boolean isFinished, boolean hadFatalError, boolean isFrozen, Long frozenBalance) {
+			boolean isSleeping, Integer sleepUntilHeight, boolean isFinished, boolean hadFatalError, boolean isFrozen, Long frozenBalance,
+			Long sleepUntilMessageTimestamp) {
 		this.ATAddress = ATAddress;
 		this.creatorPublicKey = creatorPublicKey;
 		this.creation = creation;
@@ -45,6 +47,7 @@ public class ATData {
 		this.hadFatalError = hadFatalError;
 		this.isFrozen = isFrozen;
 		this.frozenBalance = frozenBalance;
+		this.sleepUntilMessageTimestamp = sleepUntilMessageTimestamp;
 	}
 
 	/** For constructing skeleton ATData with bare minimum info. */
@@ -133,4 +136,12 @@ public class ATData {
 		this.frozenBalance = frozenBalance;
 	}
 
+	public Long getSleepUntilMessageTimestamp() {
+		return this.sleepUntilMessageTimestamp;
+	}
+
+	public void setSleepUntilMessageTimestamp(Long sleepUntilMessageTimestamp) {
+		this.sleepUntilMessageTimestamp = sleepUntilMessageTimestamp;
+	}
+
 }

src/main/java/org/qortal/data/at/ATStateData.java

@@ -10,35 +10,32 @@ public class ATStateData {
 	private Long fees;
 	private boolean isInitial;
 
+	// Qortal-AT-specific
+	private Long sleepUntilMessageTimestamp;
+
 	// Constructors
 
 	/** Create new ATStateData */
-	public ATStateData(String ATAddress, Integer height, byte[] stateData, byte[] stateHash, Long fees, boolean isInitial) {
+	public ATStateData(String ATAddress, Integer height, byte[] stateData, byte[] stateHash, Long fees,
+			boolean isInitial, Long sleepUntilMessageTimestamp) {
 		this.ATAddress = ATAddress;
 		this.height = height;
 		this.stateData = stateData;
 		this.stateHash = stateHash;
 		this.fees = fees;
 		this.isInitial = isInitial;
+		this.sleepUntilMessageTimestamp = sleepUntilMessageTimestamp;
 	}
 
 	/** For recreating per-block ATStateData from repository where not all info is needed */
 	public ATStateData(String ATAddress, int height, byte[] stateHash, Long fees, boolean isInitial) {
-		this(ATAddress, height, null, stateHash, fees, isInitial);
-	}
-
-	/** For creating ATStateData from serialized bytes when we don't have all the info */
-	public ATStateData(String ATAddress, byte[] stateHash) {
-		// This won't ever be initial AT state from deployment as that's never serialized over the network,
-		// but generated when the DeployAtTransaction is processed locally.
-		this(ATAddress, null, null, stateHash, null, false);
+		this(ATAddress, height, null, stateHash, fees, isInitial, null);
 	}
 
 	/** For creating ATStateData from serialized bytes when we don't have all the info */
 	public ATStateData(String ATAddress, byte[] stateHash, Long fees) {
-		// This won't ever be initial AT state from deployment as that's never serialized over the network,
-		// but generated when the DeployAtTransaction is processed locally.
-		this(ATAddress, null, null, stateHash, fees, false);
+		// This won't ever be initial AT state from deployment, as that's never serialized over the network.
+		this(ATAddress, null, null, stateHash, fees, false, null);
 	}
 
 	// Getters / setters
@@ -72,4 +69,12 @@ public class ATStateData {
 		return this.isInitial;
 	}
 
+	public Long getSleepUntilMessageTimestamp() {
+		return this.sleepUntilMessageTimestamp;
+	}
+
+	public void setSleepUntilMessageTimestamp(Long sleepUntilMessageTimestamp) {
+		this.sleepUntilMessageTimestamp = sleepUntilMessageTimestamp;
+	}
+
 }

src/main/java/org/qortal/data/transaction/RegisterNameTransactionData.java

@@ -26,7 +26,7 @@ public class RegisterNameTransactionData extends TransactionData {
 	@Schema(description = "requested name", example = "my-name")
 	private String name;
 
-	@Schema(description = "simple name-related info in JSON format", example = "{ \"age\": 30 }")
+	@Schema(description = "simple name-related info in JSON or text format", example = "Registered Name on the Qortal Chain")
 	private String data;
 
 	// For internal use

src/main/java/org/qortal/data/transaction/UpdateNameTransactionData.java

@@ -26,7 +26,7 @@ public class UpdateNameTransactionData extends TransactionData {
 	@Schema(description = "new name", example = "my-new-name")
 	private String newName;
 
-	@Schema(description = "replacement simple name-related info in JSON format", example = "{ \"age\": 30 }")
+	@Schema(description = "replacement simple name-related info in JSON or text format", example = "Registered Name on the Qortal Chain")
 	private String newData;
 
 	// For internal use

src/main/java/org/qortal/gui/Gui.java

@@ -23,17 +23,21 @@ public class Gui {
 	private SysTray sysTray = null;
 
 	private Gui() {
-		this.isHeadless = GraphicsEnvironment.isHeadless();
+		try {
+			this.isHeadless = GraphicsEnvironment.isHeadless();
 
-		if (!this.isHeadless) {
-			try {
-				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-			} catch (ClassNotFoundException | InstantiationException | IllegalAccessException
-					| UnsupportedLookAndFeelException e) {
-				// Use whatever look-and-feel comes by default then
+			if (!this.isHeadless) {
+				try {
+					UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
+				} catch (ClassNotFoundException | InstantiationException | IllegalAccessException
+						| UnsupportedLookAndFeelException e) {
+					// Use whatever look-and-feel comes by default then
+				}
+
+				showSplash();
 			}
-
-			showSplash();
+		} catch (Exception e) {
+			LOGGER.info("Unable to initialize GUI: {}", e.getMessage());
 		}
 	}
 

src/main/java/org/qortal/gui/SplashFrame.java

@@ -1,15 +1,11 @@
 package org.qortal.gui;
 
-import java.awt.BorderLayout;
-import java.awt.Image;
+import java.awt.*;
 import java.util.ArrayList;
 import java.util.List;
-import java.awt.Dimension;
-import java.awt.Graphics;
 import java.awt.image.BufferedImage;
 
-import javax.swing.JDialog;
-import javax.swing.JPanel;
+import javax.swing.*;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -19,46 +15,53 @@ public class SplashFrame {
 	protected static final Logger LOGGER = LogManager.getLogger(SplashFrame.class);
 
 	private static SplashFrame instance;
-	private JDialog splashDialog;
+	private JFrame splashDialog;
 
 	@SuppressWarnings("serial")
 	public static class SplashPanel extends JPanel {
 		private BufferedImage image;
 
+		private String defaultSplash = "Qlogo_512.png";
+
 		public SplashPanel() {
-			image = Gui.loadImage("splash.png");
-			this.setPreferredSize(new Dimension(image.getWidth(), image.getHeight()));
-			this.setLayout(new BorderLayout());
+			image = Gui.loadImage(defaultSplash);
+
+			setOpaque(false);
+			setLayout(new GridBagLayout());
 		}
 
 		@Override
 		protected void paintComponent(Graphics g) {
 			super.paintComponent(g);
-			g.drawImage(image, 0, 0, null);
+			g.drawImage(image, 0, 0, getWidth(), getHeight(), this);
+		}
+
+		@Override
+		public Dimension getPreferredSize() {
+			return new Dimension(500, 500);
 		}
 	}
 
 	private SplashFrame() {
-		this.splashDialog = new JDialog();
+		this.splashDialog = new JFrame();
 
 		List<Image> icons = new ArrayList<>();
 		icons.add(Gui.loadImage("icons/icon16.png"));
-		icons.add(Gui.loadImage("icons/icon32.png"));
+		icons.add(Gui.loadImage("icons/qortal_ui_tray_synced.png"));
+		icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing_time-alt.png"));
+		icons.add(Gui.loadImage("icons/qortal_ui_tray_minting.png"));
+		icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing.png"));
 		icons.add(Gui.loadImage("icons/icon64.png"));
-		icons.add(Gui.loadImage("icons/icon128.png"));
+		icons.add(Gui.loadImage("icons/Qlogo_128.png"));
 		this.splashDialog.setIconImages(icons);
 
-		this.splashDialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
-		this.splashDialog.setTitle("qortal");
-		this.splashDialog.setContentPane(new SplashPanel());
-
+		this.splashDialog.getContentPane().add(new SplashPanel());
+		this.splashDialog.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
 		this.splashDialog.setUndecorated(true);
-		this.splashDialog.setModal(false);
 		this.splashDialog.pack();
 		this.splashDialog.setLocationRelativeTo(null);
-		this.splashDialog.toFront();
+		this.splashDialog.setBackground(new Color(0,0,0,0));
 		this.splashDialog.setVisible(true);
-		this.splashDialog.repaint();
 	}
 
 	public static SplashFrame getInstance() {

src/main/java/org/qortal/gui/SysTray.java

@@ -61,7 +61,7 @@ public class SysTray {
 		this.popupMenu = createJPopupMenu();
 
 		// Build TrayIcon without AWT PopupMenu (which doesn't support Unicode)...
-		this.trayIcon = new TrayIcon(Gui.loadImage("icons/icon32.png"), "qortal", null);
+		this.trayIcon = new TrayIcon(Gui.loadImage("icons/qortal_ui_tray_synced.png"), "qortal", null);
 		// ...and attach mouse listener instead so we can use JPopupMenu (which does support Unicode)
 		this.trayIcon.addMouseListener(new MouseAdapter() {
 			@Override
@@ -289,6 +289,29 @@ public class SysTray {
 			this.trayIcon.setToolTip(text);
 	}
 
+	public void setTrayIcon(int iconid) {
+		if (trayIcon != null) {
+			try {
+				switch (iconid) {
+					case 1:
+						this.trayIcon.setImage(Gui.loadImage("icons/qortal_ui_tray_syncing_time-alt.png"));
+						break;
+					case 2:
+						this.trayIcon.setImage(Gui.loadImage("icons/qortal_ui_tray_minting.png"));
+						break;
+					case 3:
+						this.trayIcon.setImage(Gui.loadImage("icons/qortal_ui_tray_syncing.png"));
+						break;
+					case 4:
+						this.trayIcon.setImage(Gui.loadImage("icons/qortal_ui_tray_synced.png"));
+						break;
+				}
+			} catch (NullPointerException e) {
+				LOGGER.info("Unable to set tray icon");
+			}
+		}
+	}
+
 	public void dispose() {
 		if (trayIcon != null)
 			SystemTray.getSystemTray().remove(this.trayIcon);

src/main/java/org/qortal/list/ResourceList.java

@@ -0,0 +1,157 @@
+package org.qortal.list;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.json.JSONArray;
+import org.qortal.settings.Settings;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ResourceList {
+
+    private static final Logger LOGGER = LogManager.getLogger(ResourceList.class);
+
+    private String category;
+    private String resourceName;
+    private List<String> list;
+
+    /**
+     * ResourceList
+     * Creates or updates a list for the purpose of tracking resources on the Qortal network
+     * This can be used for local blocking, or even for curating and sharing content lists
+     * Lists are backed off to JSON files (in the lists folder) to ease sharing between nodes and users
+     *
+     * @param category - for instance "blacklist", "whitelist", or "userlist"
+     * @param resourceName - for instance "address", "poll", or "group"
+     * @throws IOException
+     */
+    public ResourceList(String category, String resourceName) throws IOException {
+        this.category = category;
+        this.resourceName = resourceName;
+        this.list = new ArrayList<>();
+        this.load();
+    }
+
+
+    /* Filesystem */
+
+    private Path getFilePath() {
+        String pathString = String.format("%s%s%s_%s.json", Settings.getInstance().getListsPath(),
+                File.separator, this.resourceName, this.category);
+        return Paths.get(pathString);
+    }
+
+    public void save() throws IOException {
+        if (this.resourceName == null) {
+            throw new IllegalStateException("Can't save list with missing resource name");
+        }
+        if (this.category == null) {
+            throw new IllegalStateException("Can't save list with missing category");
+        }
+        String jsonString = ResourceList.listToJSONString(this.list);
+        Path filePath = this.getFilePath();
+
+        // Create parent directory if needed
+        try {
+            Files.createDirectories(filePath.getParent());
+        } catch (IOException e) {
+            throw new IllegalStateException("Unable to create lists directory");
+        }
+
+        BufferedWriter writer = new BufferedWriter(new FileWriter(filePath.toString()));
+        writer.write(jsonString);
+        writer.close();
+    }
+
+    private boolean load() throws IOException {
+        Path path = this.getFilePath();
+        File resourceListFile = new File(path.toString());
+        if (!resourceListFile.exists()) {
+            return false;
+        }
+
+        try {
+            String jsonString = new String(Files.readAllBytes(path));
+            this.list = ResourceList.listFromJSONString(jsonString);
+        } catch (IOException e) {
+            throw new IOException(String.format("Couldn't read contents from file %s", path.toString()));
+        }
+
+        return true;
+    }
+
+    public boolean revert() {
+        try {
+            return this.load();
+        } catch (IOException e) {
+            LOGGER.info("Unable to revert {} {}", this.resourceName, this.category);
+        }
+        return false;
+    }
+
+
+    /* List management */
+
+    public void add(String resource) {
+        if (resource == null || this.list == null) {
+            return;
+        }
+        if (!this.contains(resource)) {
+            this.list.add(resource);
+        }
+    }
+
+    public void remove(String resource) {
+        if (resource == null || this.list == null) {
+            return;
+        }
+        this.list.remove(resource);
+    }
+
+    public boolean contains(String resource) {
+        if (resource == null || this.list == null) {
+            return false;
+        }
+        return this.list.contains(resource);
+    }
+
+
+    /* Utils */
+
+    public static String listToJSONString(List<String> list) {
+        if (list == null) {
+            return null;
+        }
+        JSONArray items = new JSONArray();
+        for (String item : list) {
+            items.put(item);
+        }
+        return items.toString(4);
+    }
+
+    private static List<String> listFromJSONString(String jsonString) {
+        if (jsonString == null) {
+            return null;
+        }
+        JSONArray jsonList = new JSONArray(jsonString);
+        List<String> resourceList = new ArrayList<>();
+        for (int i=0; i<jsonList.length(); i++) {
+            String item = (String)jsonList.get(i);
+            resourceList.add(item);
+        }
+        return resourceList;
+    }
+
+    public String getJSONString() {
+        return ResourceList.listToJSONString(this.list);
+    }
+
+}

src/main/java/org/qortal/list/ResourceListManager.java

@@ -0,0 +1,95 @@
+package org.qortal.list;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.IOException;
+import java.util.List;
+
+public class ResourceListManager {
+
+    private static final Logger LOGGER = LogManager.getLogger(ResourceListManager.class);
+
+    private static ResourceListManager instance;
+    private ResourceList addressBlacklist;
+
+    public ResourceListManager() {
+        try {
+            this.addressBlacklist = new ResourceList("blacklist", "address");
+        } catch (IOException e) {
+            LOGGER.info("Error while loading address blacklist. Blocking is currently unavailable.");
+        }
+    }
+
+    public static synchronized ResourceListManager getInstance() {
+        if (instance == null) {
+            instance = new ResourceListManager();
+        }
+
+        return instance;
+    }
+
+    public boolean addAddressToBlacklist(String address, boolean save) {
+        try {
+            this.addressBlacklist.add(address);
+            if (save) {
+                this.addressBlacklist.save();
+            }
+            return true;
+
+        } catch (IllegalStateException | IOException e) {
+            LOGGER.info("Unable to add address to blacklist", e);
+            return false;
+        }
+    }
+
+    public boolean removeAddressFromBlacklist(String address, boolean save) {
+        try {
+            this.addressBlacklist.remove(address);
+
+            if (save) {
+                this.addressBlacklist.save();
+            }
+            return true;
+
+        } catch (IllegalStateException | IOException e) {
+            LOGGER.info("Unable to remove address from blacklist", e);
+            return false;
+        }
+    }
+
+    public boolean isAddressInBlacklist(String address) {
+        if (this.addressBlacklist == null) {
+            return false;
+        }
+        return this.addressBlacklist.contains(address);
+    }
+
+    public void saveBlacklist() {
+        if (this.addressBlacklist == null) {
+            return;
+        }
+
+        try {
+            this.addressBlacklist.save();
+        } catch (IOException e) {
+            LOGGER.info("Unable to save blacklist - reverting back to last saved state");
+            this.addressBlacklist.revert();
+        }
+    }
+
+    public void revertBlacklist() {
+        if (this.addressBlacklist == null) {
+            return;
+        }
+        this.addressBlacklist.revert();
+    }
+
+    public String getBlacklistJSONString() {
+        if (this.addressBlacklist == null) {
+            return null;
+        }
+        return this.addressBlacklist.getJSONString();
+    }
+
+}

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

@@ -78,9 +78,10 @@ public class Name {
 		// Set name's last-updated timestamp
 		this.nameData.setUpdated(updateNameTransactionData.getTimestamp());
 
-		// Update name and data where appropriate
+		// Update name, reduced name, and data where appropriate
 		if (!updateNameTransactionData.getNewName().isEmpty()) {
 			this.nameData.setName(updateNameTransactionData.getNewName());
+			this.nameData.setReducedName(updateNameTransactionData.getReducedNewName());
 
 			// If we're changing the name, we need to delete old entry
 			this.repository.getNameRepository().delete(updateNameTransactionData.getName());
@@ -106,6 +107,9 @@ public class Name {
 		// We can find previous 'name' from update transaction
 		this.nameData.setName(updateNameTransactionData.getName());
 
+		// We can derive the previous 'reduced name' from the previous name
+		this.nameData.setReducedName(Unicode.sanitize(updateNameTransactionData.getName()));
+
 		// We might need to hunt for previous data value
 		if (!updateNameTransactionData.getNewData().isEmpty())
 			this.nameData.setData(findPreviousData(nameReference));
@@ -261,4 +265,8 @@ public class Name {
 		return previousTransactionData.getTimestamp();
 	}
 
+	public NameData getNameData() {
+		return this.nameData;
+	}
+
 }

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

@@ -72,7 +72,8 @@ public class Network {
     private static final String[] INITIAL_PEERS = new String[]{
             "node1.qortal.org", "node2.qortal.org", "node3.qortal.org", "node4.qortal.org", "node5.qortal.org",
             "node6.qortal.org", "node7.qortal.org", "node8.qortal.org", "node9.qortal.org", "node10.qortal.org",
-            "node.qortal.ru", "node2.qortal.ru", "node3.qortal.ru", "node.qortal.uk"
+            "node.qortal.ru", "node2.qortal.ru", "node3.qortal.ru", "node.qortal.uk", "node22.qortal.org",
+            "cinfu1.crowetic.com", "node.cwd.systems"
     };
 
     private static final long NETWORK_EPC_KEEPALIVE = 10L; // seconds
@@ -80,6 +81,8 @@ public class Network {
     public static final int MAX_SIGNATURES_PER_REPLY = 500;
     public static final int MAX_BLOCK_SUMMARIES_PER_REPLY = 500;
 
+    private static final long DISCONNECTION_CHECK_INTERVAL = 10 * 1000L; // milliseconds
+
     // Generate our node keys / ID
     private final Ed25519PrivateKeyParameters edPrivateKeyParams = new Ed25519PrivateKeyParameters(new SecureRandom());
     private final Ed25519PublicKeyParameters edPublicKeyParams = edPrivateKeyParams.generatePublicKey();
@@ -89,6 +92,8 @@ public class Network {
     private final int minOutboundPeers;
     private final int maxPeers;
 
+    private long nextDisconnectionCheck = 0L;
+
     private final List<PeerData> allKnownPeers = new ArrayList<>();
     private final List<Peer> connectedPeers = new ArrayList<>();
     private final List<PeerAddress> selfPeers = new ArrayList<>();
@@ -576,6 +581,8 @@ public class Network {
                 // 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);
+
+                this.checkLongestConnection(now);
             }
 
             // Any left?
@@ -633,6 +640,29 @@ public class Network {
         return null;
     }
 
+    private void checkLongestConnection(Long now) {
+        if (now == null || now < nextDisconnectionCheck) {
+            return;
+        }
+
+        // Find peers that have reached their maximum connection age, and disconnect them
+        List<Peer> peersToDisconnect = this.connectedPeers.stream()
+                .filter(peer -> !peer.isSyncInProgress())
+                .filter(peer -> peer.hasReachedMaxConnectionAge())
+                .collect(Collectors.toList());
+
+        if (peersToDisconnect != null && peersToDisconnect.size() > 0) {
+            for (Peer peer : peersToDisconnect) {
+                LOGGER.info("Forcing disconnection of peer {} because connection age ({} ms) " +
+                        "has reached the maximum ({} ms)", peer, peer.getConnectionAge(), peer.getMaxConnectionAge());
+                peer.disconnect("Connection age too old");
+            }
+        }
+
+        // Check again after a minimum fixed interval
+        nextDisconnectionCheck = now + DISCONNECTION_CHECK_INTERVAL;
+    }
+
     // Peer callbacks
 
     protected void wakeupChannelSelector() {

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

@@ -79,6 +79,7 @@ public class Peer {
     private Handshake handshakeStatus = Handshake.STARTED;
     private volatile boolean handshakeMessagePending = false;
     private long handshakeComplete = -1L;
+    private long maxConnectionAge = 0L;
 
     /**
      * Timestamp of when socket was accepted, or connected.
@@ -96,6 +97,8 @@ public class Peer {
 
     byte[] ourChallenge;
 
+    private boolean syncInProgress = false;
+
     // Versioning
     public static final Pattern VERSION_PATTERN = Pattern.compile(Controller.VERSION_PREFIX
             + "(\\d{1,3})\\.(\\d{1,5})\\.(\\d{1,5})");
@@ -192,10 +195,24 @@ public class Peer {
             this.handshakeStatus = handshakeStatus;
             if (handshakeStatus.equals(Handshake.COMPLETED)) {
                 this.handshakeComplete = System.currentTimeMillis();
+                this.generateRandomMaxConnectionAge();
             }
         }
     }
 
+    private void generateRandomMaxConnectionAge() {
+        // Retrieve the min and max connection time from the settings, and calculate the range
+        final int minPeerConnectionTime = Settings.getInstance().getMinPeerConnectionTime();
+        final int maxPeerConnectionTime = Settings.getInstance().getMaxPeerConnectionTime();
+        final int peerConnectionTimeRange = maxPeerConnectionTime - minPeerConnectionTime;
+
+        // Generate a random number between the min and the max
+        Random random = new Random();
+        this.maxConnectionAge = (random.nextInt(peerConnectionTimeRange) + minPeerConnectionTime) * 1000L;
+        LOGGER.debug(String.format("[%s] Generated max connection age for peer %s. Min: %ds, max: %ds, range: %ds, random max: %dms", this.peerConnectionId, this, minPeerConnectionTime, maxPeerConnectionTime, peerConnectionTimeRange, this.maxConnectionAge));
+
+    }
+
     protected void resetHandshakeMessagePending() {
         this.handshakeMessagePending = false;
     }
@@ -325,6 +342,14 @@ public class Peer {
         }
     }
 
+    public boolean isSyncInProgress() {
+        return this.syncInProgress;
+    }
+
+    public void setSyncInProgress(boolean syncInProgress) {
+        this.syncInProgress = syncInProgress;
+    }
+
     @Override
     public String toString() {
         // Easier, and nicer output, than peer.getRemoteSocketAddress()
@@ -777,4 +802,12 @@ public class Peer {
         }
         return handshakeComplete;
     }
+
+    public long getMaxConnectionAge() {
+        return maxConnectionAge;
+    }
+
+    public boolean hasReachedMaxConnectionAge() {
+        return this.getConnectionAge() > this.getMaxConnectionAge();
+    }
 }

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

@@ -6,6 +6,7 @@ import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.qortal.data.network.OnlineAccountData;
 import org.qortal.transform.Transformer;
@@ -25,7 +26,7 @@ public class GetOnlineAccountsMessage extends Message {
 	private GetOnlineAccountsMessage(int id, List<OnlineAccountData> onlineAccounts) {
 		super(id, MessageType.GET_ONLINE_ACCOUNTS);
 
-		this.onlineAccounts = onlineAccounts;
+		this.onlineAccounts = onlineAccounts.stream().limit(MAX_ACCOUNT_COUNT).collect(Collectors.toList());
 	}
 
 	public List<OnlineAccountData> getOnlineAccounts() {
@@ -35,12 +36,9 @@ public class GetOnlineAccountsMessage extends Message {
 	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
 		final int accountCount = bytes.getInt();
 
-		if (accountCount > MAX_ACCOUNT_COUNT)
-			return null;
-
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
 
-		for (int i = 0; i < accountCount; ++i) {
+		for (int i = 0; i < Math.min(MAX_ACCOUNT_COUNT, accountCount); ++i) {
 			long timestamp = bytes.getLong();
 
 			byte[] publicKey = new byte[Transformer.PUBLIC_KEY_LENGTH];

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

@@ -6,6 +6,7 @@ import java.io.UnsupportedEncodingException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.qortal.data.network.OnlineAccountData;
 import org.qortal.transform.Transformer;
@@ -25,7 +26,7 @@ public class OnlineAccountsMessage extends Message {
 	private OnlineAccountsMessage(int id, List<OnlineAccountData> onlineAccounts) {
 		super(id, MessageType.ONLINE_ACCOUNTS);
 
-		this.onlineAccounts = onlineAccounts;
+		this.onlineAccounts = onlineAccounts.stream().limit(MAX_ACCOUNT_COUNT).collect(Collectors.toList());
 	}
 
 	public List<OnlineAccountData> getOnlineAccounts() {
@@ -35,12 +36,9 @@ public class OnlineAccountsMessage extends Message {
 	public static Message fromByteBuffer(int id, ByteBuffer bytes) throws UnsupportedEncodingException {
 		final int accountCount = bytes.getInt();
 
-		if (accountCount > MAX_ACCOUNT_COUNT)
-			return null;
-
 		List<OnlineAccountData> onlineAccounts = new ArrayList<>(accountCount);
 
-		for (int i = 0; i < accountCount; ++i) {
+		for (int i = 0; i < Math.min(MAX_ACCOUNT_COUNT, accountCount); ++i) {
 			long timestamp = bytes.getLong();
 
 			byte[] signature = new byte[Transformer.SIGNATURE_LENGTH];

src/main/java/org/qortal/repository/ATRepository.java

@@ -103,7 +103,7 @@ public interface ATRepository {
 	/**
 	 * Returns all ATStateData for a given block height.
 	 * <p>
-	 * Unlike <tt>getATState</tt>, only returns ATStateData saved at the given height.
+	 * Unlike <tt>getATState</tt>, only returns <i>partial</i> ATStateData saved at the given height.
 	 *
 	 * @param height
 	 *            - block height

src/main/java/org/qortal/repository/hsqldb/HSQLDBATRepository.java

@@ -32,7 +32,7 @@ public class HSQLDBATRepository implements ATRepository {
 	public ATData fromATAddress(String atAddress) throws DataException {
 		String sql = "SELECT creator, created_when, version, asset_id, code_bytes, code_hash, "
 				+ "is_sleeping, sleep_until_height, is_finished, had_fatal_error, "
-				+ "is_frozen, frozen_balance "
+				+ "is_frozen, frozen_balance, sleep_until_message_timestamp "
 				+ "FROM ATs "
 				+ "WHERE AT_address = ? LIMIT 1";
 
@@ -60,8 +60,13 @@ public class HSQLDBATRepository implements ATRepository {
 			if (frozenBalance == 0 && resultSet.wasNull())
 				frozenBalance = null;
 
+			Long sleepUntilMessageTimestamp = resultSet.getLong(13);
+			if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+				sleepUntilMessageTimestamp = null;
+
 			return new ATData(atAddress, creatorPublicKey, created, version, assetId, codeBytes, codeHash,
-					isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance);
+					isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance,
+					sleepUntilMessageTimestamp);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch AT from repository", e);
 		}
@@ -94,7 +99,7 @@ public class HSQLDBATRepository implements ATRepository {
 	public List<ATData> getAllExecutableATs() throws DataException {
 		String sql = "SELECT AT_address, creator, created_when, version, asset_id, code_bytes, code_hash, "
 				+ "is_sleeping, sleep_until_height, had_fatal_error, "
-				+ "is_frozen, frozen_balance "
+				+ "is_frozen, frozen_balance, sleep_until_message_timestamp "
 				+ "FROM ATs "
 				+ "WHERE is_finished = false "
 				+ "ORDER BY created_when ASC";
@@ -128,8 +133,13 @@ public class HSQLDBATRepository implements ATRepository {
 				if (frozenBalance == 0 && resultSet.wasNull())
 					frozenBalance = null;
 
+				Long sleepUntilMessageTimestamp = resultSet.getLong(13);
+				if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+					sleepUntilMessageTimestamp = null;
+
 				ATData atData = new ATData(atAddress, creatorPublicKey, created, version, assetId, codeBytes, codeHash,
-						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance);
+						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance,
+						sleepUntilMessageTimestamp);
 
 				executableATs.add(atData);
 			} while (resultSet.next());
@@ -147,7 +157,7 @@ public class HSQLDBATRepository implements ATRepository {
 
 		sql.append("SELECT AT_address, creator, created_when, version, asset_id, code_bytes, ")
 				.append("is_sleeping, sleep_until_height, is_finished, had_fatal_error, ")
-				.append("is_frozen, frozen_balance ")
+				.append("is_frozen, frozen_balance, sleep_until_message_timestamp ")
 				.append("FROM ATs ")
 				.append("WHERE code_hash = ? ");
 		bindParams.add(codeHash);
@@ -191,8 +201,13 @@ public class HSQLDBATRepository implements ATRepository {
 				if (frozenBalance == 0 && resultSet.wasNull())
 					frozenBalance = null;
 
+				Long sleepUntilMessageTimestamp = resultSet.getLong(13);
+				if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+					sleepUntilMessageTimestamp = null;
+
 				ATData atData = new ATData(atAddress, creatorPublicKey, created, version, assetId, codeBytes, codeHash,
-						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance);
+						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance,
+						sleepUntilMessageTimestamp);
 
 				matchingATs.add(atData);
 			} while (resultSet.next());
@@ -210,7 +225,7 @@ public class HSQLDBATRepository implements ATRepository {
 
 		sql.append("SELECT AT_address, creator, created_when, version, asset_id, code_bytes, ")
 				.append("is_sleeping, sleep_until_height, is_finished, had_fatal_error, ")
-				.append("is_frozen, frozen_balance, code_hash ")
+				.append("is_frozen, frozen_balance, code_hash, sleep_until_message_timestamp ")
 				.append("FROM ");
 
 		// (VALUES (?), (?), ...) AS ATCodeHashes (code_hash)
@@ -264,9 +279,10 @@ public class HSQLDBATRepository implements ATRepository {
 					frozenBalance = null;
 
 				byte[] codeHash = resultSet.getBytes(13);
+				Long sleepUntilMessageTimestamp = resultSet.getLong(14);
 
 				ATData atData = new ATData(atAddress, creatorPublicKey, created, version, assetId, codeBytes, codeHash,
-						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance);
+						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance, sleepUntilMessageTimestamp);
 
 				matchingATs.add(atData);
 			} while (resultSet.next());
@@ -305,7 +321,7 @@ public class HSQLDBATRepository implements ATRepository {
 				.bind("code_bytes", atData.getCodeBytes()).bind("code_hash", atData.getCodeHash())
 				.bind("is_sleeping", atData.getIsSleeping()).bind("sleep_until_height", atData.getSleepUntilHeight())
 				.bind("is_finished", atData.getIsFinished()).bind("had_fatal_error", atData.getHadFatalError()).bind("is_frozen", atData.getIsFrozen())
-				.bind("frozen_balance", atData.getFrozenBalance());
+				.bind("frozen_balance", atData.getFrozenBalance()).bind("sleep_until_message_timestamp", atData.getSleepUntilMessageTimestamp());
 
 		try {
 			saveHelper.execute(this.repository);
@@ -328,7 +344,7 @@ public class HSQLDBATRepository implements ATRepository {
 
 	@Override
 	public ATStateData getATStateAtHeight(String atAddress, int height) throws DataException {
-		String sql = "SELECT state_data, state_hash, fees, is_initial "
+		String sql = "SELECT state_data, state_hash, fees, is_initial, sleep_until_message_timestamp "
 				+ "FROM ATStates "
 				+ "LEFT OUTER JOIN ATStatesData USING (AT_address, height) "
 				+ "WHERE ATStates.AT_address = ? AND ATStates.height = ? "
@@ -343,7 +359,11 @@ public class HSQLDBATRepository implements ATRepository {
 			long fees = resultSet.getLong(3);
 			boolean isInitial = resultSet.getBoolean(4);
 
-			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
+			Long sleepUntilMessageTimestamp = resultSet.getLong(5);
+			if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+				sleepUntilMessageTimestamp = null;
+
+			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial, sleepUntilMessageTimestamp);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch AT state from repository", e);
 		}
@@ -351,7 +371,7 @@ public class HSQLDBATRepository implements ATRepository {
 
 	@Override
 	public ATStateData getLatestATState(String atAddress) throws DataException {
-		String sql = "SELECT height, state_data, state_hash, fees, is_initial "
+		String sql = "SELECT height, state_data, state_hash, fees, is_initial, sleep_until_message_timestamp "
 				+ "FROM ATStates "
 				+ "JOIN ATStatesData USING (AT_address, height) "
 				+ "WHERE ATStates.AT_address = ? "
@@ -370,7 +390,11 @@ public class HSQLDBATRepository implements ATRepository {
 			long fees = resultSet.getLong(4);
 			boolean isInitial = resultSet.getBoolean(5);
 
-			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
+			Long sleepUntilMessageTimestamp = resultSet.getLong(6);
+			if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+				sleepUntilMessageTimestamp = null;
+
+			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial, sleepUntilMessageTimestamp);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch latest AT state from repository", e);
 		}
@@ -383,10 +407,10 @@ public class HSQLDBATRepository implements ATRepository {
 		StringBuilder sql = new StringBuilder(1024);
 		List<Object> bindParams = new ArrayList<>();
 
-		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial "
+		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial, FinalATStates.sleep_until_message_timestamp "
 				+ "FROM ATs "
 				+ "CROSS JOIN LATERAL("
-					+ "SELECT height, state_data, state_hash, fees, is_initial "
+					+ "SELECT height, state_data, state_hash, fees, is_initial, sleep_until_message_timestamp "
 					+ "FROM ATStates "
 					+ "JOIN ATStatesData USING (AT_address, height) "
 					+ "WHERE ATStates.AT_address = ATs.AT_address ");
@@ -440,7 +464,11 @@ public class HSQLDBATRepository implements ATRepository {
 				long fees = resultSet.getLong(5);
 				boolean isInitial = resultSet.getBoolean(6);
 
-				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
+				Long sleepUntilMessageTimestamp = resultSet.getLong(7);
+				if (sleepUntilMessageTimestamp == 0 && resultSet.wasNull())
+					sleepUntilMessageTimestamp = null;
+
+				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial, sleepUntilMessageTimestamp);
 
 				atStates.add(atStateData);
 			} while (resultSet.next());
@@ -471,7 +499,7 @@ public class HSQLDBATRepository implements ATRepository {
 		StringBuilder sql = new StringBuilder(1024);
 		List<Object> bindParams = new ArrayList<>();
 
-		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial "
+		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial, sleep_until_message_timestamp "
 				+ "FROM ATs "
 				+ "CROSS JOIN LATERAL("
 					+ "SELECT height, state_data, state_hash, fees, is_initial "
@@ -526,8 +554,10 @@ public class HSQLDBATRepository implements ATRepository {
 				byte[] stateHash = resultSet.getBytes(4);
 				long fees = resultSet.getLong(5);
 				boolean isInitial = resultSet.getBoolean(6);
+				Long sleepUntilMessageTimestamp = resultSet.getLong(7);
 
-				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
+				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial,
+						sleepUntilMessageTimestamp);
 
 				atStates.add(atStateData);
 			} while (resultSet.next());
@@ -662,7 +692,8 @@ public class HSQLDBATRepository implements ATRepository {
 
 		atStatesSaver.bind("AT_address", atStateData.getATAddress()).bind("height", atStateData.getHeight())
 				.bind("state_hash", atStateData.getStateHash())
-				.bind("fees", atStateData.getFees()).bind("is_initial", atStateData.isInitial());
+				.bind("fees", atStateData.getFees()).bind("is_initial", atStateData.isInitial())
+				.bind("sleep_until_message_timestamp", atStateData.getSleepUntilMessageTimestamp());
 
 		try {
 			atStatesSaver.execute(this.repository);

src/main/java/org/qortal/repository/hsqldb/HSQLDBDatabaseUpdates.java

@@ -699,7 +699,7 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("CHECKPOINT");
 					break;
 
-				case 30:
+				case 30: {
 					// Split AT state data off to new table for better performance/management.
 
 					if (!wasPristine && !"mem".equals(HSQLDBRepository.getDbPathname(connection.getMetaData().getURL()))) {
@@ -774,6 +774,7 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("ALTER TABLE ATStatesNew RENAME TO ATStates");
 					stmt.execute("CHECKPOINT");
 					break;
+				}
 
 				case 31:
 					// Fix latest AT state cache which was previous created as TEMPORARY
@@ -822,6 +823,51 @@ public class HSQLDBDatabaseUpdates {
 							+ "timestamp_signature Signature NOT NULL, " + TRANSACTION_KEYS + ")");
 					break;
 
+				case 34: {
+					// AT sleep-until-message support
+					LOGGER.info("Altering AT table in repository - this might take a while... (approx. 20 seconds on high-spec)");
+					stmt.execute("ALTER TABLE ATs ADD sleep_until_message_timestamp BIGINT");
+
+					// Create new AT-states table with new column
+					stmt.execute("CREATE TABLE ATStatesNew ("
+							+ "AT_address QortalAddress, height INTEGER NOT NULL, state_hash ATStateHash NOT NULL, "
+							+ "fees QortalAmount NOT NULL, is_initial BOOLEAN NOT NULL, sleep_until_message_timestamp BIGINT, "
+							+ "PRIMARY KEY (AT_address, height), "
+							+ "FOREIGN KEY (AT_address) REFERENCES ATs (AT_address) ON DELETE CASCADE)");
+					stmt.execute("SET TABLE ATStatesNew NEW SPACE");
+					stmt.execute("CHECKPOINT");
+
+					// Add the height index
+					LOGGER.info("Adding index to AT states table...");
+					stmt.execute("CREATE INDEX ATStatesNewHeightIndex ON ATStatesNew (height)");
+					stmt.execute("CHECKPOINT");
+
+					ResultSet resultSet = stmt.executeQuery("SELECT height FROM Blocks ORDER BY height DESC LIMIT 1");
+					final int blockchainHeight = resultSet.next() ? resultSet.getInt(1) : 0;
+					final int heightStep = 100;
+
+					LOGGER.info("Altering AT states table in repository - this might take a while... (approx. 3 mins on high-spec)");
+					for (int minHeight = 1; minHeight < blockchainHeight; minHeight += heightStep) {
+						stmt.execute("INSERT INTO ATStatesNew ("
+								+ "SELECT AT_address, height, state_hash, fees, is_initial, NULL "
+								+ "FROM ATStates "
+								+ "WHERE height BETWEEN " + minHeight + " AND " + (minHeight + heightStep - 1)
+								+ ")");
+						stmt.execute("COMMIT");
+
+						int processed = Math.min(minHeight + heightStep - 1, blockchainHeight);
+						double percentage = (double)processed / (double)blockchainHeight * 100.0f;
+						LOGGER.info(String.format("Processed %d of %d blocks (%.1f%%)", processed, blockchainHeight, percentage));
+					}
+					stmt.execute("CHECKPOINT");
+
+					stmt.execute("DROP TABLE ATStates");
+					stmt.execute("ALTER TABLE ATStatesNew RENAME TO ATStates");
+					stmt.execute("ALTER INDEX ATStatesNewHeightIndex RENAME TO ATStatesHeightIndex");
+					stmt.execute("CHECKPOINT");
+					break;
+				}
+
 				default:
 					// nothing to do
 					return false;

src/main/java/org/qortal/repository/hsqldb/HSQLDBRepository.java

@@ -55,7 +55,7 @@ public class HSQLDBRepository implements Repository {
 
 	private static final Logger LOGGER = LogManager.getLogger(HSQLDBRepository.class);
 
-	private static final Object CHECKPOINT_LOCK = new Object();
+	public static final Object CHECKPOINT_LOCK = new Object();
 
 	// "serialization failure"
 	private static final Integer DEADLOCK_ERROR_CODE = Integer.valueOf(-4861);
@@ -703,8 +703,11 @@ public class HSQLDBRepository implements Repository {
 	private ResultSet checkedExecuteResultSet(PreparedStatement preparedStatement, Object... objects) throws SQLException {
 		bindStatementParams(preparedStatement, objects);
 
-		if (!preparedStatement.execute())
-			throw new SQLException("Fetching from database produced no results");
+		// synchronize to block new executions if checkpointing in progress
+		synchronized (CHECKPOINT_LOCK) {
+			if (!preparedStatement.execute())
+				throw new SQLException("Fetching from database produced no results");
+		}
 
 		ResultSet resultSet = preparedStatement.getResultSet();
 		if (resultSet == null)
@@ -1056,4 +1059,4 @@ public class HSQLDBRepository implements Repository {
 		return DEADLOCK_ERROR_CODE.equals(e.getErrorCode());
 	}
 
-}
+}

src/main/java/org/qortal/repository/hsqldb/HSQLDBSaver.java

@@ -61,13 +61,15 @@ public class HSQLDBSaver {
 	public boolean execute(HSQLDBRepository repository) throws SQLException {
 		String sql = this.formatInsertWithPlaceholders();
 
-		try {
-			PreparedStatement preparedStatement = repository.prepareStatement(sql);
-			this.bindValues(preparedStatement);
+		synchronized (HSQLDBRepository.CHECKPOINT_LOCK) {
+			try {
+				PreparedStatement preparedStatement = repository.prepareStatement(sql);
+				this.bindValues(preparedStatement);
 
-			return preparedStatement.execute();
-		} catch (SQLException e) {
-			throw repository.examineException(e);
+				return preparedStatement.execute();
+			} catch (SQLException e) {
+				throw repository.examineException(e);
+			}
 		}
 	}
 

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

@@ -23,6 +23,7 @@ import org.eclipse.persistence.jaxb.UnmarshallerProperties;
 import org.qortal.block.BlockChain;
 import org.qortal.crosschain.Bitcoin.BitcoinNet;
 import org.qortal.crosschain.Litecoin.LitecoinNet;
+import org.qortal.crosschain.Dogecoin.DogecoinNet;
 
 // All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)
@@ -67,6 +68,9 @@ public class Settings {
 	};
 	private Boolean apiRestricted;
 	private String apiKey = null;
+	/** Whether to disable API key or loopback address checking
+	 * IMPORTANT: do not disable for shared nodes or low-security local networks */
+	private boolean apiKeyDisabled = false;
 	private boolean apiLoggingEnabled = false;
 	private boolean apiDocumentationEnabled = false;
 	// Both of these need to be set for API to use SSL
@@ -93,7 +97,7 @@ public class Settings {
 	private int blockCacheSize = 10;
 
 	/** How long to keep old, full, AT state data (ms). */
-	private long atStatesMaxLifetime = 2 * 7 * 24 * 60 * 60 * 1000L; // milliseconds
+	private long atStatesMaxLifetime = 5 * 24 * 60 * 60 * 1000L; // milliseconds
 	/** How often to attempt AT state trimming (ms). */
 	private long atStatesTrimInterval = 5678L; // milliseconds
 	/** Block height range to scan for trimmable AT states.<br>
@@ -132,10 +136,16 @@ public class Settings {
 	 * If false, sync will be blocked both ways, and they will not appear in the peers list */
 	private boolean allowConnectionsWithOlderPeerVersions = true;
 
+	/** Minimum time (in seconds) that we should attempt to remain connected to a peer for */
+	private int minPeerConnectionTime = 2 * 60; // seconds
+	/** Maximum time (in seconds) that we should attempt to remain connected to a peer for */
+	private int maxPeerConnectionTime = 20 * 60; // seconds
+
 	// Which blockchains this node is running
 	private String blockchainConfig = null; // use default from resources
 	private BitcoinNet bitcoinNet = BitcoinNet.MAIN;
 	private LitecoinNet litecoinNet = LitecoinNet.MAIN;
+	private DogecoinNet dogecoinNet = DogecoinNet.MAIN;
 	// Also crosschain-related:
 	/** Whether to show SysTray pop-up notifications when trade-bot entries change state */
 	private boolean tradebotSystrayEnabled = false;
@@ -154,6 +164,9 @@ public class Settings {
 		"https://raw.githubusercontent.com@151.101.16.133/Qortal/qortal/%s/qortal.update"
 	};
 
+	// Lists
+	private String listsPath = "lists";
+
 	/** Array of NTP server hostnames. */
 	private String[] ntpServers = new String[] {
 		"pool.ntp.org",
@@ -346,6 +359,10 @@ public class Settings {
 		return this.apiKey;
 	}
 
+	public boolean isApiKeyDisabled() {
+		return this.apiKeyDisabled;
+	}
+
 	public boolean isApiLoggingEnabled() {
 		return this.apiLoggingEnabled;
 	}
@@ -423,6 +440,10 @@ public class Settings {
 
 	public boolean getAllowConnectionsWithOlderPeerVersions() { return this.allowConnectionsWithOlderPeerVersions; }
 
+	public int getMinPeerConnectionTime() { return this.minPeerConnectionTime; }
+
+	public int getMaxPeerConnectionTime() { return this.maxPeerConnectionTime; }
+
 	public String getBlockchainConfig() {
 		return this.blockchainConfig;
 	}
@@ -435,6 +456,10 @@ public class Settings {
 		return this.litecoinNet;
 	}
 
+	public DogecoinNet getDogecoinNet() {
+		return this.dogecoinNet;
+	}
+
 	public boolean isTradebotSystrayEnabled() {
 		return this.tradebotSystrayEnabled;
 	}
@@ -459,6 +484,10 @@ public class Settings {
 		return this.autoUpdateRepos;
 	}
 
+	public String getListsPath() {
+		return this.listsPath;
+	}
+
 	public String[] getNtpServers() {
 		return this.ntpServers;
 	}

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

@@ -48,6 +48,11 @@ public class AccountFlagsTransaction extends Transaction {
 		return ValidationResult.NO_FLAG_PERMISSION;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		Account target = this.getTarget();

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

@@ -49,6 +49,11 @@ public class AccountLevelTransaction extends Transaction {
 		return ValidationResult.NO_FLAG_PERMISSION;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		Account target = getTarget();

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

@@ -84,6 +84,11 @@ public class AddGroupAdminTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group adminship
@@ -98,4 +103,4 @@ public class AddGroupAdminTransaction extends Transaction {
 		group.unpromoteToAdmin(this.addGroupAdminTransactionData);
 	}
 
-}
+}

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

@@ -60,6 +60,11 @@ public class ArbitraryTransaction extends Transaction {
 				arbitraryTransactionData.getFee());
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Wrap and delegate payment processing to Payment class.

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

@@ -80,6 +80,11 @@ public class AtTransaction extends Transaction {
 		return Arrays.equals(atAccount.getLastReference(), atTransactionData.getReference());
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public ValidationResult isValid() throws DataException {
 		// Check recipient address is valid

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

@@ -6,6 +6,7 @@ import java.util.List;
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
 import org.qortal.block.BlockChain;
+import org.qortal.controller.repository.NamesDatabaseIntegrityCheck;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.naming.NameData;
 import org.qortal.data.transaction.BuyNameTransactionData;
@@ -98,6 +99,17 @@ public class BuyNameTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) transactionData;
+
+		// Rebuild this name in the Names table from the transaction history
+		// This is necessary because in some rare cases names can be missing from the Names table after registration
+		// but we have been unable to reproduce the issue and track down the root cause
+		NamesDatabaseIntegrityCheck namesDatabaseIntegrityCheck = new NamesDatabaseIntegrityCheck();
+		namesDatabaseIntegrityCheck.rebuildName(buyNameTransactionData.getName(), this.repository);
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Buy Name

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

@@ -62,6 +62,11 @@ public class CancelAssetOrderTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Mark Order as completed so no more trades can happen

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

@@ -83,6 +83,11 @@ public class CancelGroupBanTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -83,6 +83,11 @@ public class CancelGroupInviteTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -79,6 +79,11 @@ public class CancelSellNameTransaction extends Transaction {
 
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Name

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

@@ -11,6 +11,7 @@ import org.qortal.crypto.MemoryPoW;
 import org.qortal.data.transaction.ChatTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.group.Group;
+import org.qortal.list.ResourceListManager;
 import org.qortal.repository.DataException;
 import org.qortal.repository.GroupRepository;
 import org.qortal.repository.Repository;
@@ -134,10 +135,21 @@ public class ChatTransaction extends Transaction {
 		return true;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public ValidationResult isValid() throws DataException {
 		// Nonce checking is done via isSignatureValid() as that method is only called once per import
 
+		// Check for blacklisted author by address
+		ResourceListManager listManager = ResourceListManager.getInstance();
+		if (listManager.isAddressInBlacklist(this.chatTransactionData.getSender())) {
+			return ValidationResult.ADDRESS_IN_BLACKLIST;
+		}
+
 		// If we exist in the repository then we've been imported as unconfirmed,
 		// but we don't want to make it into a block, so return fake non-OK result.
 		if (this.repository.getTransactionRepository().exists(this.chatTransactionData.getSignature()))

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

@@ -135,6 +135,11 @@ public class CreateAssetOrderTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Order Id is transaction's signature

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

@@ -92,6 +92,11 @@ public class CreateGroupTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Create Group

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

@@ -106,6 +106,11 @@ public class CreatePollTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Publish poll to allow voting

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

@@ -203,6 +203,11 @@ public class DeployAtTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		ensureATAddress(this.deployAtTransactionData);

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

@@ -100,6 +100,11 @@ public class GenesisTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		Account recipient = new Account(repository, this.genesisTransactionData.getRecipient());

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

@@ -66,6 +66,11 @@ public class GroupApprovalTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Find previous approval decision (if any) by this admin for pending transaction

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

@@ -87,6 +87,11 @@ public class GroupBanTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -88,6 +88,11 @@ public class GroupInviteTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -89,6 +89,11 @@ public class GroupKickTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -92,6 +92,11 @@ public class IssueAssetTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Issue asset

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

@@ -67,6 +67,11 @@ public class JoinGroupTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -67,6 +67,11 @@ public class LeaveGroupTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group Membership

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

@@ -239,6 +239,11 @@ public class MessageTransaction extends Transaction {
 				getPaymentData(), this.messageTransactionData.getFee(), true);
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// If we have no amount then there's nothing to do

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

@@ -67,6 +67,11 @@ public class MultiPaymentTransaction extends Transaction {
 		return new Payment(this.repository).isProcessable(this.multiPaymentTransactionData.getSenderPublicKey(), payments, this.multiPaymentTransactionData.getFee());
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Wrap and delegate payment processing to Payment class.

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

@@ -61,6 +61,11 @@ public class PaymentTransaction extends Transaction {
 		return new Payment(this.repository).isProcessable(this.paymentTransactionData.getSenderPublicKey(), getPaymentData(), this.paymentTransactionData.getFee());
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Wrap and delegate payment processing to Payment class.

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

@@ -149,6 +149,11 @@ public class PresenceTransaction extends Transaction {
 		return true;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public ValidationResult isValid() throws DataException {
 		// Nonce checking is done via isSignatureValid() as that method is only called once per import

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

@@ -80,6 +80,11 @@ public class PublicizeTransaction extends Transaction {
 		return true;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public ValidationResult isValid() throws DataException {
 		// There can be only one

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

@@ -6,6 +6,7 @@ import java.util.List;
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
 import org.qortal.block.BlockChain;
+import org.qortal.controller.repository.NamesDatabaseIntegrityCheck;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.transaction.RegisterNameTransactionData;
 import org.qortal.data.transaction.TransactionData;
@@ -88,6 +89,17 @@ public class RegisterNameTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		RegisterNameTransactionData registerNameTransactionData = (RegisterNameTransactionData) transactionData;
+
+		// Rebuild this name in the Names table from the transaction history
+		// This is necessary because in some rare cases names can be missing from the Names table after registration
+		// but we have been unable to reproduce the issue and track down the root cause
+		NamesDatabaseIntegrityCheck namesDatabaseIntegrityCheck = new NamesDatabaseIntegrityCheck();
+		namesDatabaseIntegrityCheck.rebuildName(registerNameTransactionData.getName(), this.repository);
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Register Name

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

@@ -87,6 +87,11 @@ public class RemoveGroupAdminTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Update Group adminship
@@ -107,4 +112,4 @@ public class RemoveGroupAdminTransaction extends Transaction {
 		this.repository.getTransactionRepository().save(this.removeGroupAdminTransactionData);
 	}
 
-}
+}

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

@@ -159,6 +159,11 @@ public class RewardShareTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		PublicKeyAccount mintingAccount = getMintingAccount();

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

@@ -5,6 +5,7 @@ import java.util.List;
 
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
+import org.qortal.controller.repository.NamesDatabaseIntegrityCheck;
 import org.qortal.data.naming.NameData;
 import org.qortal.data.transaction.SellNameTransactionData;
 import org.qortal.data.transaction.TransactionData;
@@ -89,6 +90,17 @@ public class SellNameTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		SellNameTransactionData sellNameTransactionData = (SellNameTransactionData) transactionData;
+
+		// Rebuild this name in the Names table from the transaction history
+		// This is necessary because in some rare cases names can be missing from the Names table after registration
+		// but we have been unable to reproduce the issue and track down the root cause
+		NamesDatabaseIntegrityCheck namesDatabaseIntegrityCheck = new NamesDatabaseIntegrityCheck();
+		namesDatabaseIntegrityCheck.rebuildName(sellNameTransactionData.getName(), this.repository);
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Sell Name

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

@@ -56,6 +56,11 @@ public class SetGroupTransaction extends Transaction {
 		return ValidationResult.OK;
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		Account creator = getCreator();

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

@@ -247,6 +247,7 @@ public abstract class Transaction {
 		INVALID_GROUP_BLOCK_DELAY(93),
 		INCORRECT_NONCE(94),
 		INVALID_TIMESTAMP_SIGNATURE(95),
+		ADDRESS_IN_BLACKLIST(96),
 		INVALID_BUT_OK(999),
 		NOT_YET_RELEASED(1000);
 
@@ -790,6 +791,8 @@ public abstract class Transaction {
 			// Fix up approval status
 			this.setInitialApprovalStatus();
 
+			this.preProcess();
+
 			ValidationResult validationResult = this.isValidUnconfirmed();
 			if (validationResult != ValidationResult.OK)
 				return validationResult;
@@ -890,6 +893,14 @@ public abstract class Transaction {
 		return ValidationResult.OK;
 	}
 
+	/**
+	 * * Pre-process a transaction before validating or processing the block
+	 * This allows for any database integrity checks prior to validation.
+	 *
+	 * @throws DataException
+	 */
+	public abstract void preProcess() throws DataException;
+
 	/**
 	 * Actually process a transaction, updating the blockchain.
 	 * <p>

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

@@ -61,6 +61,11 @@ public class TransferAssetTransaction extends Transaction {
 		return new Payment(this.repository).isProcessable(this.transferAssetTransactionData.getSenderPublicKey(), getPaymentData(), this.transferAssetTransactionData.getFee());
 	}
 
+	@Override
+	public void preProcess() throws DataException {
+		// Nothing to do
+	}
+
 	@Override
 	public void process() throws DataException {
 		// Wrap asset transfer as a payment and delegate processing to Payment class.