Keep existing findCommonBlocksWithPeers() and comparePeers() behaviour prior to consensus switchover, to reduce the number of variables.

This reverts commit 0eebfe4a8c.

WindowsInstaller/Qortal.aip

@@ -17,10 +17,10 @@
     <ROW Property="Manufacturer" Value="Qortal"/>
     <ROW Property="MsiLogging" MultiBuildValue="DefaultBuild:vp"/>
     <ROW Property="NTP_GOOD" Value="false"/>
-    <ROW Property="ProductCode" Value="1033:{8EF8A9D7-8BD1-436A-B9E7-2F1F8AEFB507} 1049:{7A9E536E-93C2-47B5-9F6C-C4866C0DE68F} 2052:{E87CA833-375A-4A57-97C0-C4BADA8AEE59} 2057:{E5E73017-0CE6-429D-BC57-A588C63761F5} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{7DED0630-60A3-438A-B857-D95BD16213F1} 1049:{4A7BAAA1-E9EC-4E92-8963-34420EC1E3F4} 2052:{F3448469-4E4F-4600-AE05-DF7669B267E3} 2057:{0B980BC5-4C80-4A98-A4D2-B32D134AA276} " Type="16"/>
     <ROW Property="ProductLanguage" Value="2057"/>
     <ROW Property="ProductName" Value="Qortal"/>
-    <ROW Property="ProductVersion" Value="3.3.0" Type="32"/>
+    <ROW Property="ProductVersion" Value="3.3.5" Type="32"/>
     <ROW Property="RECONFIG_NTP" Value="true"/>
     <ROW Property="REMOVE_BLOCKCHAIN" Value="YES" Type="4"/>
     <ROW Property="REPAIR_BLOCKCHAIN" Value="YES" Type="4"/>
@@ -212,7 +212,7 @@
     <ROW Component="ADDITIONAL_LICENSE_INFO_71" ComponentId="{12A3ADBE-BB7A-496C-8869-410681E6232F}" Directory_="jdk.zipfs_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_71" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_8" ComponentId="{D53AD95E-CF96-4999-80FC-5812277A7456}" Directory_="java.naming_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_8" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_9" ComponentId="{6B7EA9B0-5D17-47A8-B78C-FACE86D15E01}" Directory_="java.net.http_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_9" Type="0"/>
-    <ROW Component="AI_CustomARPName" ComponentId="{99CB0542-3A63-45C2-B955-8ADAA2A85A91}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
+    <ROW Component="AI_CustomARPName" ComponentId="{191AD445-72DF-4850-BB4A-FE92D4B62BCF}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
     <ROW Component="AI_ExePath" ComponentId="{3644948D-AE0B-41BB-9FAF-A79E70490A08}" Directory_="APPDIR" Attributes="260" KeyPath="AI_ExePath"/>
     <ROW Component="APPDIR" ComponentId="{680DFDDE-3FB4-47A5-8FF5-934F576C6F91}" Directory_="APPDIR" Attributes="0"/>
     <ROW Component="AccessBridgeCallbacks.h" ComponentId="{288055D1-1062-47A3-AA44-5601B4E38AED}" Directory_="bridge_Dir" Attributes="0" KeyPath="AccessBridgeCallbacks.h" Type="0"/>

pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>3.3.1</version>
+	<version>3.3.5</version>
 	<packaging>jar</packaging>
 	<properties>
 		<skipTests>true</skipTests>

src/main/java/org/qortal/ApplyUpdate.java

@@ -37,7 +37,7 @@ public class ApplyUpdate {
 	private static final String JAVA_TOOL_OPTIONS_NAME = "JAVA_TOOL_OPTIONS";
 	private static final String JAVA_TOOL_OPTIONS_VALUE = "-XX:MaxRAMFraction=4";
 
-	private static final long CHECK_INTERVAL = 10 * 1000L; // ms
+	private static final long CHECK_INTERVAL = 30 * 1000L; // ms
 	private static final int MAX_ATTEMPTS = 12;
 
 	public static void main(String[] args) {

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

@@ -3,9 +3,12 @@ package org.qortal.block;
 import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.toMap;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.math.RoundingMode;
+import java.nio.charset.StandardCharsets;
 import java.text.DecimalFormat;
 import java.text.NumberFormat;
 import java.util.*;
@@ -118,6 +121,8 @@ public class Block {
 
 	/** Remote/imported/loaded AT states */
 	protected List<ATStateData> atStates;
+	/** Remote hash of AT states - in lieu of full AT state data in {@code atStates} */
+	protected byte[] atStatesHash;
 	/** Locally-generated AT states */
 	protected List<ATStateData> ourAtStates;
 	/** Locally-generated AT fees */
@@ -255,7 +260,7 @@ public class Block {
 	 * Constructs new Block using passed transaction and AT states.
 	 * <p>
 	 * This constructor typically used when receiving a serialized block over the network.
-	 * 
+	 *
 	 * @param repository
 	 * @param blockData
 	 * @param transactions
@@ -281,6 +286,35 @@ public class Block {
 		this.blockData.setTotalFees(totalFees);
 	}
 
+	/**
+	 * Constructs new Block using passed transaction and minimal AT state info.
+	 * <p>
+	 * This constructor typically used when receiving a serialized block over the network.
+	 *
+	 * @param repository
+	 * @param blockData
+	 * @param transactions
+	 * @param atStatesHash
+	 */
+	public Block(Repository repository, BlockData blockData, List<TransactionData> transactions, byte[] atStatesHash) {
+		this(repository, blockData);
+
+		this.transactions = new ArrayList<>();
+
+		long totalFees = 0;
+
+		// We have to sum fees too
+		for (TransactionData transactionData : transactions) {
+			this.transactions.add(Transaction.fromData(repository, transactionData));
+			totalFees += transactionData.getFee();
+		}
+
+		this.atStatesHash = atStatesHash;
+		totalFees += this.blockData.getATFees();
+
+		this.blockData.setTotalFees(totalFees);
+	}
+
 	/**
 	 * Constructs new Block with empty transaction list, using passed minter account.
 	 * 
@@ -1194,7 +1228,7 @@ public class Block {
 	 */
 	private ValidationResult areAtsValid() throws DataException {
 		// Locally generated AT states should be valid so no need to re-execute them
-		if (this.ourAtStates == this.getATStates()) // Note object reference compare
+		if (this.ourAtStates != null && this.ourAtStates == this.atStates) // Note object reference compare
 			return ValidationResult.OK;
 
 		// Generate local AT states for comparison
@@ -1208,8 +1242,33 @@ public class Block {
 		if (this.ourAtFees != this.blockData.getATFees())
 			return ValidationResult.AT_STATES_MISMATCH;
 
-		// Note: this.atStates fully loaded thanks to this.getATStates() call above
-		for (int s = 0; s < this.atStates.size(); ++s) {
+		// If we have a single AT states hash then compare that in preference
+		if (this.atStatesHash != null) {
+			int atBytesLength = blockData.getATCount() * BlockTransformer.AT_ENTRY_LENGTH;
+			ByteArrayOutputStream atHashBytes = new ByteArrayOutputStream(atBytesLength);
+
+			try {
+				for (ATStateData atStateData : this.ourAtStates) {
+					atHashBytes.write(atStateData.getATAddress().getBytes(StandardCharsets.UTF_8));
+					atHashBytes.write(atStateData.getStateHash());
+					atHashBytes.write(Longs.toByteArray(atStateData.getFees()));
+				}
+			} catch (IOException e) {
+				throw new DataException("Couldn't validate AT states hash due to serialization issue?", e);
+			}
+
+			byte[] ourAtStatesHash = Crypto.digest(atHashBytes.toByteArray());
+			if (!Arrays.equals(ourAtStatesHash, this.atStatesHash))
+				return ValidationResult.AT_STATES_MISMATCH;
+
+			// Use our AT state data from now on
+			this.atStates = this.ourAtStates;
+			return ValidationResult.OK;
+		}
+
+		// Note: this.atStates fully loaded thanks to this.getATStates() call:
+		this.getATStates();
+		for (int s = 0; s < this.ourAtStates.size(); ++s) {
 			ATStateData ourAtState = this.ourAtStates.get(s);
 			ATStateData theirAtState = this.atStates.get(s);
 

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

@@ -69,8 +69,10 @@ public class BlockChain {
 		newBlockSigHeight,
 		shareBinFix,
 		calcChainWeightTimestamp,
+		newConsensusTimestamp,
 		transactionV5Timestamp,
-		transactionV6Timestamp;
+		transactionV6Timestamp,
+		disableReferenceTimestamp
 	}
 
 	// Custom transaction fees
@@ -402,6 +404,10 @@ public class BlockChain {
 		return this.featureTriggers.get(FeatureTrigger.calcChainWeightTimestamp.name()).longValue();
 	}
 
+	public long getNewConsensusTimestamp() {
+		return this.featureTriggers.get(FeatureTrigger.newConsensusTimestamp.name()).longValue();
+	}
+
 	public long getTransactionV5Timestamp() {
 		return this.featureTriggers.get(FeatureTrigger.transactionV5Timestamp.name()).longValue();
 	}
@@ -410,6 +416,10 @@ public class BlockChain {
 		return this.featureTriggers.get(FeatureTrigger.transactionV6Timestamp.name()).longValue();
 	}
 
+	public long getDisableReferenceTimestamp() {
+		return this.featureTriggers.get(FeatureTrigger.disableReferenceTimestamp.name()).longValue();
+	}
+
 	// More complex getters for aspects that change by height or timestamp
 
 	public long getRewardAtHeight(int ourHeight) {

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

@@ -212,6 +212,14 @@ public class BlockMinter extends Thread {
 				// Do we need to build any potential new blocks?
 				List<PrivateKeyAccount> newBlocksMintingAccounts = mintingAccountsData.stream().map(accountData -> new PrivateKeyAccount(repository, accountData.getPrivateKey())).collect(Collectors.toList());
 
+				// We might need to sit the next block out, if one of our minting accounts signed the previous one
+				final byte[] previousBlockMinter = previousBlockData.getMinterPublicKey();
+				final boolean mintedLastBlock = mintingAccountsData.stream().anyMatch(mintingAccount -> Arrays.equals(mintingAccount.getPublicKey(), previousBlockMinter));
+				if (mintedLastBlock) {
+					LOGGER.trace(String.format("One of our keys signed the last block, so we won't sign the next one"));
+					continue;
+				}
+
 				if (parentSignatureForLastLowWeightBlock != null) {
 					// The last iteration found a higher weight block in the network, so sleep for a while
 					// to allow is to sync the higher weight chain. We are sleeping here rather than when

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

@@ -715,6 +715,24 @@ public class Controller extends Thread {
 		return lastMisbehaved != null && lastMisbehaved > NTP.getTime() - MISBEHAVIOUR_COOLOFF;
 	};
 
+	/** True if peer has unknown height or lower height. */
+	public static final Predicate<Peer> hasShorterBlockchain = peer -> {
+		BlockData ourLatestBlockData = getInstance().getChainTip();
+		int ourHeight = ourLatestBlockData.getHeight();
+		final PeerChainTipData peerChainTipData = peer.getChainTipData();
+
+		// Ensure we have chain tip data for this peer
+		if (peerChainTipData == null)
+			return true;
+
+		// Remove if peer is at a lower height than us
+		Integer peerHeight = peerChainTipData.getLastHeight();
+		if (peerHeight == null || peerHeight < ourHeight)
+			return true;
+
+		return false;
+	};
+
 	public static final Predicate<Peer> hasNoRecentBlock = peer -> {
 		final Long minLatestBlockTimestamp = getMinimumLatestBlockTimestamp();
 		final PeerChainTipData peerChainTipData = peer.getChainTipData();
@@ -1362,6 +1380,18 @@ public class Controller extends Thread {
 
 			Block block = new Block(repository, blockData);
 
+			// V2 support
+			if (peer.getPeersVersion() >= BlockV2Message.MIN_PEER_VERSION) {
+				Message blockMessage = new BlockV2Message(block);
+				blockMessage.setId(message.getId());
+				if (!peer.sendMessage(blockMessage)) {
+					peer.disconnect("failed to send block");
+					// Don't fall-through to caching because failure to send might be from failure to build message
+					return;
+				}
+				return;
+			}
+
 			CachedBlockMessage blockMessage = new CachedBlockMessage(block);
 			blockMessage.setId(message.getId());
 

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

@@ -173,7 +173,7 @@ public class LiteNode {
         }
 
         if (responseMessage == null) {
-            LOGGER.info("Peer didn't respond to {} message", peer, message.getType());
+            LOGGER.info("Peer {} didn't respond to {} message", peer, message.getType());
             return null;
         }
         else if (responseMessage.getType() != expectedResponseMessageType) {

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

@@ -26,14 +26,7 @@ import org.qortal.event.Event;
 import org.qortal.event.EventBus;
 import org.qortal.network.Network;
 import org.qortal.network.Peer;
-import org.qortal.network.message.BlockMessage;
-import org.qortal.network.message.BlockSummariesMessage;
-import org.qortal.network.message.GetBlockMessage;
-import org.qortal.network.message.GetBlockSummariesMessage;
-import org.qortal.network.message.GetSignaturesV2Message;
-import org.qortal.network.message.Message;
-import org.qortal.network.message.SignaturesMessage;
-import org.qortal.network.message.MessageType;
+import org.qortal.network.message.*;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
@@ -206,6 +199,8 @@ public class Synchronizer extends Thread {
 		if (this.isSynchronizing)
 			return true;
 
+		boolean isNewConsensusActive = NTP.getTime() >= BlockChain.getInstance().getNewConsensusTimestamp();
+
 		// Needs a mutable copy of the unmodifiableList
 		List<Peer> peers = new ArrayList<>(Network.getInstance().getImmutableHandshakedPeers());
 
@@ -234,6 +229,10 @@ public class Synchronizer extends Thread {
 		if (peers.size() < Settings.getInstance().getMinBlockchainPeers())
 			return true;
 
+		if (isNewConsensusActive)
+			// Disregard peers with a shorter chain
+			peers.removeIf(Controller.hasShorterBlockchain);
+
 		// Disregard peers that have no block signature or the same block signature as us
 		peers.removeIf(Controller.hasNoOrSameBlock);
 
@@ -242,11 +241,13 @@ public class Synchronizer extends Thread {
 
 		final int peersBeforeComparison = peers.size();
 
-		// Request recent block summaries from the remaining peers, and locate our common block with each
-		Synchronizer.getInstance().findCommonBlocksWithPeers(peers);
+		if (!isNewConsensusActive) {
+			// Request recent block summaries from the remaining peers, and locate our common block with each
+			Synchronizer.getInstance().findCommonBlocksWithPeers(peers);
 
-		// Compare the peers against each other, and against our chain, which will return an updated list excluding those without common blocks
-		peers = Synchronizer.getInstance().comparePeers(peers);
+			// Compare the peers against each other, and against our chain, which will return an updated list excluding those without common blocks
+			peers = Synchronizer.getInstance().comparePeers(peers);
+		}
 
 		// We may have added more inferior chain tips when comparing peers, so remove any peers that are currently on those chains
 		peers.removeIf(Controller.hasInferiorChainTip);
@@ -992,8 +993,13 @@ public class Synchronizer extends Thread {
 						return SynchronizationResult.NOTHING_TO_DO;
 					}
 
+					boolean isNewConsensusActive = NTP.getTime() >= BlockChain.getInstance().getNewConsensusTimestamp();
+
 					// Unless we're doing a forced sync, we might need to compare blocks after common block
-					if (!force && ourInitialHeight > commonBlockHeight) {
+					boolean isBlockComparisonNeeded = isNewConsensusActive
+							? ourInitialHeight == peerHeight
+							: ourInitialHeight > commonBlockHeight;
+					if (!force && isBlockComparisonNeeded) {
 						SynchronizationResult chainCompareResult = compareChains(repository, commonBlockData, ourLatestBlockData, peer, peerHeight, peerBlockSummaries);
 						if (chainCompareResult != SynchronizationResult.OK)
 							return chainCompareResult;
@@ -1194,27 +1200,56 @@ public class Synchronizer extends Thread {
 				peerBlockSummaries.addAll(moreBlockSummaries);
 			}
 
-			// Fetch our corresponding block summaries
-			List<BlockSummaryData> ourBlockSummaries = repository.getBlockRepository().getBlockSummaries(commonBlockHeight + 1, ourLatestBlockData.getHeight());
+			boolean isNewConsensusActive = NTP.getTime() >= BlockChain.getInstance().getNewConsensusTimestamp();
+			if (isNewConsensusActive) {
+				int parentHeight = ourLatestBlockData.getHeight() - 1;
 
-			// Populate minter account levels for both lists of block summaries
-			populateBlockSummariesMinterLevels(repository, ourBlockSummaries);
-			populateBlockSummariesMinterLevels(repository, peerBlockSummaries);
+				BlockSummaryData ourLatestBlockSummary = new BlockSummaryData(ourLatestBlockData);
+				byte[] ourParentBlockSignature = ourLatestBlockData.getReference();
 
-			final int mutualHeight = commonBlockHeight + Math.min(ourBlockSummaries.size(), peerBlockSummaries.size());
+				BlockSummaryData peersLatestBlockSummary = peerBlockSummaries.get(peerBlockSummaries.size() - 1);
+				byte[] peersParentBlockSignature = peerBlockSummaries.size() > 1
+						? peerBlockSummaries.get(peerBlockSummaries.size() - 1 - 1).getSignature()
+						: commonBlockSig;
 
-			// Calculate cumulative chain weights of both blockchain subsets, from common block to highest mutual block.
-			BigInteger ourChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, ourBlockSummaries, mutualHeight);
-			BigInteger peerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, peerBlockSummaries, mutualHeight);
+				// Populate minter account levels for both lists of block summaries
+				populateBlockSummariesMinterLevels(repository, Collections.singletonList(ourLatestBlockSummary));
+				populateBlockSummariesMinterLevels(repository, Collections.singletonList(peersLatestBlockSummary));
 
-			NumberFormat accurateFormatter = new DecimalFormat("0.################E0");
-			LOGGER.debug(String.format("commonBlockHeight: %d, commonBlockSig: %.8s, ourBlockSummaries.size(): %d, peerBlockSummaries.size(): %d", commonBlockHeight, Base58.encode(commonBlockSig), ourBlockSummaries.size(), peerBlockSummaries.size()));
-			LOGGER.debug(String.format("Our chain weight: %s, peer's chain weight: %s (higher is better)", accurateFormatter.format(ourChainWeight), accurateFormatter.format(peerChainWeight)));
+				BigInteger ourChainWeight = Block.calcBlockWeight(parentHeight, ourParentBlockSignature, ourLatestBlockSummary);
+				BigInteger peerChainWeight = Block.calcBlockWeight(parentHeight, peersParentBlockSignature, peersLatestBlockSummary);
 
-			// If our blockchain has greater weight then don't synchronize with peer
-			if (ourChainWeight.compareTo(peerChainWeight) >= 0) {
-				LOGGER.debug(String.format("Not synchronizing with peer %s as we have better blockchain", peer));
-				return SynchronizationResult.INFERIOR_CHAIN;
+				NumberFormat accurateFormatter = new DecimalFormat("0.################E0");
+				LOGGER.debug(String.format("Our chain weight: %s, peer's chain weight: %s (higher is better)", accurateFormatter.format(ourChainWeight), accurateFormatter.format(peerChainWeight)));
+
+				// If our blockchain has greater weight then don't synchronize with peer
+				if (ourChainWeight.compareTo(peerChainWeight) >= 0) {
+					LOGGER.debug(String.format("Not synchronizing with peer %s as we have better blockchain", peer));
+					return SynchronizationResult.INFERIOR_CHAIN;
+				}
+			} else {
+				// Fetch our corresponding block summaries
+				List<BlockSummaryData> ourBlockSummaries = repository.getBlockRepository().getBlockSummaries(commonBlockHeight + 1, ourLatestBlockData.getHeight());
+
+				// Populate minter account levels for both lists of block summaries
+				populateBlockSummariesMinterLevels(repository, ourBlockSummaries);
+				populateBlockSummariesMinterLevels(repository, peerBlockSummaries);
+
+				final int mutualHeight = commonBlockHeight + Math.min(ourBlockSummaries.size(), peerBlockSummaries.size());
+
+				// Calculate cumulative chain weights of both blockchain subsets, from common block to highest mutual block.
+				BigInteger ourChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, ourBlockSummaries, mutualHeight);
+				BigInteger peerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, peerBlockSummaries, mutualHeight);
+
+				NumberFormat accurateFormatter = new DecimalFormat("0.################E0");
+				LOGGER.debug(String.format("commonBlockHeight: %d, commonBlockSig: %.8s, ourBlockSummaries.size(): %d, peerBlockSummaries.size(): %d", commonBlockHeight, Base58.encode(commonBlockSig), ourBlockSummaries.size(), peerBlockSummaries.size()));
+				LOGGER.debug(String.format("Our chain weight: %s, peer's chain weight: %s (higher is better)", accurateFormatter.format(ourChainWeight), accurateFormatter.format(peerChainWeight)));
+
+				// If our blockchain has greater weight then don't synchronize with peer
+				if (ourChainWeight.compareTo(peerChainWeight) >= 0) {
+					LOGGER.debug(String.format("Not synchronizing with peer %s as we have better blockchain", peer));
+					return SynchronizationResult.INFERIOR_CHAIN;
+				}
 			}
 		}
 
@@ -1579,12 +1614,23 @@ public class Synchronizer extends Thread {
 		Message getBlockMessage = new GetBlockMessage(signature);
 
 		Message message = peer.getResponse(getBlockMessage);
-		if (message == null || message.getType() != MessageType.BLOCK)
+		if (message == null)
 			return null;
 
-		BlockMessage blockMessage = (BlockMessage) message;
+		switch (message.getType()) {
+			case BLOCK: {
+				BlockMessage blockMessage = (BlockMessage) message;
+				return new Block(repository, blockMessage.getBlockData(), blockMessage.getTransactions(), blockMessage.getAtStates());
+			}
 
-		return new Block(repository, blockMessage.getBlockData(), blockMessage.getTransactions(), blockMessage.getAtStates());
+			case BLOCK_V2: {
+				BlockV2Message blockMessage = (BlockV2Message) message;
+				return new Block(repository, blockMessage.getBlockData(), blockMessage.getTransactions(), blockMessage.getAtStatesHash());
+			}
+
+			default:
+				return null;
+		}
 	}
 
 	public void populateBlockSummariesMinterLevels(Repository repository, List<BlockSummaryData> blockSummaries) throws DataException {

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

@@ -2,6 +2,7 @@ package org.qortal.controller;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.data.block.BlockData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.network.Network;
 import org.qortal.network.Peer;
@@ -98,10 +99,12 @@ public class TransactionImporter extends Thread {
      * @return a list of TransactionData objects, with valid signatures.
      */
     private List<TransactionData> getCachedSigValidTransactions() {
-        return this.incomingTransactions.entrySet().stream()
-                .filter(t -> Boolean.TRUE.equals(t.getValue()))
-                .map(Map.Entry::getKey)
-                .collect(Collectors.toList());
+        synchronized (this.incomingTransactions) {
+            return this.incomingTransactions.entrySet().stream()
+                    .filter(t -> Boolean.TRUE.equals(t.getValue()))
+                    .map(Map.Entry::getKey)
+                    .collect(Collectors.toList());
+        }
     }
 
     /**
@@ -135,6 +138,9 @@ public class TransactionImporter extends Thread {
 
             boolean isLiteNode = Settings.getInstance().isLite();
 
+            // We need the latest block in order to check for expired transactions
+            BlockData latestBlock = Controller.getInstance().getChainTip();
+
             // Signature validation round - does not require blockchain lock
             for (Map.Entry<TransactionData, Boolean> transactionEntry : incomingTransactionsCopy.entrySet()) {
                 // Quick exit?
@@ -144,6 +150,20 @@ public class TransactionImporter extends Thread {
 
                 TransactionData transactionData = transactionEntry.getKey();
                 Transaction transaction = Transaction.fromData(repository, transactionData);
+                String signature58 = Base58.encode(transactionData.getSignature());
+
+                Long now = NTP.getTime();
+                if (now == null) {
+                    return;
+                }
+
+                // Drop expired transactions before they are considered "sig valid"
+                if (latestBlock != null && transaction.getDeadline() <= latestBlock.getTimestamp()) {
+                    LOGGER.debug("Removing expired {} transaction {} from import queue", transactionData.getType().name(), signature58);
+                    removeIncomingTransaction(transactionData.getSignature());
+                    invalidUnconfirmedTransactions.put(signature58, (now + EXPIRED_TRANSACTION_RECHECK_INTERVAL));
+                    continue;
+                }
 
                 // Only validate signature if we haven't already done so
                 Boolean isSigValid = transactionEntry.getValue();
@@ -158,13 +178,11 @@ public class TransactionImporter extends Thread {
                     }
 
                     if (!transaction.isSignatureValid()) {
-                        String signature58 = Base58.encode(transactionData.getSignature());
-
                         LOGGER.debug("Ignoring {} transaction {} with invalid signature", transactionData.getType().name(), signature58);
                         removeIncomingTransaction(transactionData.getSignature());
 
                         // Also add to invalidIncomingTransactions map
-                        Long now = NTP.getTime();
+                        now = NTP.getTime();
                         if (now != null) {
                             Long expiry = now + INVALID_TRANSACTION_RECHECK_INTERVAL;
                             LOGGER.trace("Adding invalid transaction {} to invalidUnconfirmedTransactions...", signature58);

src/main/java/org/qortal/controller/tradebot/BitcoinACCTv3TradeBot.java

@@ -0,0 +1,885 @@
+package org.qortal.controller.tradebot;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.*;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.*;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+/**
+ * Performing cross-chain trading steps on behalf of user.
+ * <p>
+ * We deal with three different independent state-spaces here:
+ * <ul>
+ * 	<li>Qortal blockchain</li>
+ * 	<li>Foreign blockchain</li>
+ * 	<li>Trade-bot entries</li>
+ * </ul>
+ */
+public class BitcoinACCTv3TradeBot implements AcctTradeBot {
+
+	private static final Logger LOGGER = LogManager.getLogger(BitcoinACCTv3TradeBot.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 BitcoinACCTv3TradeBot 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 BitcoinACCTv3TradeBot() {
+	}
+
+	public static synchronized BitcoinACCTv3TradeBot getInstance() {
+		if (instance == null)
+			instance = new BitcoinACCTv3TradeBot();
+
+		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 BTC.
+	 * <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 Bitcoin) 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'/Bitcoin public key hash - used by Alice's P2SH scripts to allow redeem</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>BTC 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 Bitcoin receiving address into public key hash (we only support P2PKH at this time)
+		Address bitcoinReceivingAddress;
+		try {
+			bitcoinReceivingAddress = Address.fromString(Bitcoin.getInstance().getNetworkParameters(), tradeBotCreateRequest.receivingAddress);
+		} catch (AddressFormatException e) {
+			throw new DataException("Unsupported Bitcoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+		}
+		if (bitcoinReceivingAddress.getOutputScriptType() != ScriptType.P2PKH)
+			throw new DataException("Unsupported Bitcoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+
+		byte[] bitcoinReceivingAccountInfo = bitcoinReceivingAddress.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/BTC ACCT";
+		String description = "QORT/BTC cross-chain trade";
+		String aTType = "ACCT";
+		String tags = "ACCT QORT BTC";
+		byte[] creationBytes = BitcoinACCTv3.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, BitcoinACCTv3.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.BITCOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				tradeBotCreateRequest.foreignAmount, null, null, null, bitcoinReceivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Built AT %s. Waiting for deployment", atAddress));
+
+		// Attempt to backup the trade bot data
+		TradeBot.backupTradeBotData(repository, null);
+
+		// Return to user for signing and broadcast as we don't have their Qortal private key
+		try {
+			return DeployAtTransactionTransformer.toBytes(deployAtTransactionData);
+		} catch (TransformationException e) {
+			throw new DataException("Failed to transform DEPLOY_AT transaction?", e);
+		}
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint, i.e. matching BTC to an existing offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a Bitcoin 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 Bitcoin 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 Bitcoin main-net)
+	 * or 'tprv' for (Bitcoin 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 Bitcoin amount expected by 'Bob'.
+	 * <p>
+	 * If the Bitcoin 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 Bitcoin 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, BitcoinACCTv3.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.BITCOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				crossChainTradeData.expectedForeignAmount, xprv58, null, lockTimeA, receivingPublicKeyHash);
+
+		// Attempt to backup the trade bot data
+		// Include tradeBotData as an additional parameter, since it's not in the repository yet
+		TradeBot.backupTradeBotData(repository, Arrays.asList(tradeBotData));
+
+		// Check we have enough funds via xprv58 to fund P2SH to cover expectedForeignAmount
+		long p2shFee;
+		try {
+			p2shFee = Bitcoin.getInstance().getP2shFee(now);
+		} catch (ForeignBlockchainException e) {
+			LOGGER.debug("Couldn't estimate Bitcoin 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 = Bitcoin.getInstance().deriveP2shAddress(redeemScriptBytes);
+
+		// Build transaction for funding P2SH-A
+		Transaction p2shFundingTransaction = Bitcoin.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 {
+			Bitcoin.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 = BitcoinACCTv3.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 = BitcoinACCTv3.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 Bitcoin 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;
+		}
+
+		Bitcoin bitcoin = Bitcoin.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 Bitcoin pubkeyhash and lockTime-A
+			byte[] messageData = messageTransactionData.getData();
+			BitcoinACCTv3.OfferMessageData offerMessageData = BitcoinACCTv3.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				continue;
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerBitcoinPKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+			long messageTimestamp = messageTransactionData.getTimestamp();
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(messageTimestamp, lockTimeA);
+
+			// Determine P2SH-A address and confirm funded
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(aliceForeignPublicKeyHash, lockTimeA, tradeBotData.getTradeForeignPublicKeyHash(), hashOfSecretA);
+			String p2shAddressA = bitcoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Bitcoin.getInstance().getP2shFee(feeTimestamp);
+			final long minimumAmountA = tradeBotData.getForeignAmount() + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoin.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 = BitcoinACCTv3.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 BTC 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;
+
+		Bitcoin bitcoin = Bitcoin.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 = bitcoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Bitcoin.getInstance().getP2shFee(feeTimestamp);
+			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoin.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 = BitcoinACCTv3.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 = BitcoinACCTv3.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 BTC 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 BTC funds from P2SH-A
+	 * to Bob's 'foreign'/Bitcoin trade legacy-format address, as derived from trade private key.
+	 * <p>
+	 * (This could potentially be 'improved' to send BTC 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 BTC
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
+
+			return;
+		}
+
+		byte[] secretA = BitcoinACCTv3.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
+
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		byte[] receivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+		int lockTimeA = crossChainTradeData.lockTimeA;
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTimeA, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
+		String p2shAddressA = bitcoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Bitcoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoin.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 = bitcoin.getUnspentOutputs(p2shAddressA);
+
+				Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(bitcoin.getNetworkParameters(), redeemAmount, redeemKey,
+						fundingOutputs, redeemScriptA, secretA, receivingAccountInfo);
+
+				bitcoin.broadcastTransaction(p2shRedeemTransaction);
+				break;
+			}
+		}
+
+		String receivingAddress = bitcoin.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;
+
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+		int medianBlockTime = bitcoin.getMedianBlockTime();
+		if (medianBlockTime <= lockTimeA)
+			return;
+
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+		String p2shAddressA = bitcoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Bitcoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoin.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 = bitcoin.getUnspentOutputs(p2shAddressA);
+
+				// Determine receive address for refund
+				String receiveAddress = bitcoin.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+				Address receiving = Address.fromString(bitcoin.getNetworkParameters(), receiveAddress);
+
+				Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(bitcoin.getNetworkParameters(), refundAmount, refundKey,
+						fundingOutputs, redeemScriptA, lockTimeA, receiving.getHash());
+
+				bitcoin.broadcastTransaction(p2shRefundTransaction);
+				break;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+				() -> String.format("LockTime-A reached. Refunded P2SH-A %s. Trade aborted", p2shAddressA));
+	}
+
+	/**
+	 * Returns true if Alice finds AT unexpectedly cancelled, refunded, redeemed or locked to someone else.
+	 * <p>
+	 * Will automatically update trade-bot state to <tt>ALICE_REFUNDING_A</tt> or <tt>ALICE_DONE</tt> as necessary.
+	 * 
+	 * @throws DataException
+	 * @throws ForeignBlockchainException
+	 */
+	private boolean aliceUnexpectedState(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// This is OK
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.OFFERING)
+			return false;
+
+		boolean isAtLockedToUs = tradeBotData.getTradeNativeAddress().equals(crossChainTradeData.qortalPartnerAddress);
+
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.TRADING)
+			if (isAtLockedToUs) {
+				// AT is trading with us - OK
+				return false;
+			} else {
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+						() -> String.format("AT %s trading with someone else: %s. Refunding & aborting trade", tradeBotData.getAtAddress(), crossChainTradeData.qortalPartnerAddress));
+
+				return true;
+			}
+
+		if (atData.getIsFinished() && crossChainTradeData.mode == AcctMode.REDEEMED && isAtLockedToUs) {
+			// We've redeemed already?
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+					() -> String.format("AT %s already redeemed by us. Trade completed", tradeBotData.getAtAddress()));
+		} else {
+			// Any other state is not good, so start defensive refund
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> String.format("AT %s cancelled/refunded/redeemed by someone else/invalid state. Refunding & aborting trade", tradeBotData.getAtAddress()));
+		}
+
+		return true;
+	}
+
+	private long calcFeeTimestamp(int lockTimeA, int tradeTimeout) {
+		return (lockTimeA - tradeTimeout * 60) * 1000L;
+	}
+
+}

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

@@ -94,6 +94,7 @@ public class TradeBot implements Listener {
 	private static final Map<Class<? extends ACCT>, Supplier<AcctTradeBot>> acctTradeBotSuppliers = new HashMap<>();
 	static {
 		acctTradeBotSuppliers.put(BitcoinACCTv1.class, BitcoinACCTv1TradeBot::getInstance);
+		acctTradeBotSuppliers.put(BitcoinACCTv3.class, BitcoinACCTv3TradeBot::getInstance);
 		acctTradeBotSuppliers.put(LitecoinACCTv1.class, LitecoinACCTv1TradeBot::getInstance);
 		acctTradeBotSuppliers.put(LitecoinACCTv2.class, LitecoinACCTv2TradeBot::getInstance);
 		acctTradeBotSuppliers.put(LitecoinACCTv3.class, LitecoinACCTv3TradeBot::getInstance);

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

@@ -7,6 +7,7 @@ import java.util.Map;
 
 import org.bitcoinj.core.Context;
 import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Transaction;
 import org.bitcoinj.params.MainNetParams;
 import org.bitcoinj.params.RegTestParams;
 import org.bitcoinj.params.TestNet3Params;
@@ -18,10 +19,12 @@ public class Bitcoin extends Bitcoiny {
 
 	public static final String CURRENCY_CODE = "BTC";
 
+	private static final long MINIMUM_ORDER_AMOUNT = 100000; // 0.001 BTC minimum order, due to high fees
+
 	// Temporary values until a dynamic fee system is written.
 	private static final long OLD_FEE_AMOUNT = 4_000L; // Not 5000 so that existing P2SH-B can output 1000, avoiding dust issue, leaving 4000 for fees.
 	private static final long NEW_FEE_TIMESTAMP = 1598280000000L; // milliseconds since epoch
-	private static final long NEW_FEE_AMOUNT = 10_000L;
+	private static final long NEW_FEE_AMOUNT = 6_000L;
 
 	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
 
@@ -182,6 +185,11 @@ public class Bitcoin extends Bitcoiny {
 		instance = null;
 	}
 
+	@Override
+	public long getMinimumOrderAmount() {
+		return MINIMUM_ORDER_AMOUNT;
+	}
+
 	// Actual useful methods for use by other classes
 
 	/**
@@ -195,4 +203,17 @@ public class Bitcoin extends Bitcoiny {
 		return this.bitcoinNet.getP2shFee(timestamp);
 	}
 
+	/**
+ 	* Returns bitcoinj transaction sending <tt>amount</tt> to <tt>recipient</tt> using 20 sat/byte fee.
+ 	*
+ 	* @param xprv58 BIP32 private key
+ 	* @param recipient P2PKH address
+ 	* @param amount unscaled amount
+ 	* @return transaction, or null if insufficient funds
+ 	*/
+	@Override
+	public Transaction buildSpend(String xprv58, String recipient, long amount) {
+		return buildSpend(xprv58, recipient, amount, 20L);
+	}
+
 }

src/main/java/org/qortal/crosschain/BitcoinACCTv3.java

@@ -0,0 +1,858 @@
+package org.qortal.crosschain;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.ciyam.at.*;
+import org.qortal.account.Account;
+import org.qortal.asset.Asset;
+import org.qortal.at.QortalFunctionCode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.utils.Base58;
+import org.qortal.utils.BitTwiddling;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.ciyam.at.OpCode.calcOffset;
+
+/**
+ * Cross-chain trade AT
+ * 
+ * <p>
+ * <ul>
+ * <li>Bob generates Bitcoin & 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 Bitcoin & Qortal 'trade' keys</li>
+ * 			<li>Alice funds Bitcoin 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' Bitcoin 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 Bitcoin 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 Bitcoin trade key and secret-A</li>
+ * 			<li>P2SH-A BTC funds end up at Bitcoin address determined by redeem transaction output(s)</li>
+ * 		</ul>
+ * </li>
+ * </ul>
+ */
+public class BitcoinACCTv3 implements ACCT {
+
+	private static final Logger LOGGER = LogManager.getLogger(BitcoinACCTv3.class);
+
+	public static final String NAME = BitcoinACCTv3.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("676fb9350708dafa054eb0262d655039e393c1eb4918ec582f8d45524c9b4860").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[] partnerBitcoinPKH;
+		public byte[] hashOfSecretA;
+		public long lockTimeA;
+	}
+	public static final int OFFER_MESSAGE_LENGTH = 20 /*partnerBitcoinPKH*/ + 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 Bitcoin 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 BitcoinACCTv3 instance;
+
+	private BitcoinACCTv3() {
+	}
+
+	public static synchronized BitcoinACCTv3 getInstance() {
+		if (instance == null)
+			instance = new BitcoinACCTv3();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Bitcoin.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 bitcoinPublicKeyHash 20-byte HASH160 of creator's trade Bitcoin public key
+	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
+	 * @param bitcoinAmount how much BTC the AT creator is expecting to trade
+	 * @param tradeTimeout suggested timeout for entire trade
+	 */
+	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] bitcoinPublicKeyHash, long qortAmount, long bitcoinAmount, int tradeTimeout) {
+		if (bitcoinPublicKeyHash.length != 20)
+			throw new IllegalArgumentException("Bitcoin 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 addrBitcoinPublicKeyHash = addrCounter;
+		addrCounter += 4;
+
+		final int addrQortAmount = addrCounter++;
+		final int addrBitcoinAmount = 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 addrTradeMessagePartnerBitcoinPKHOffset = addrCounter++;
+		final int addrPartnerBitcoinPKHPointer = 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 addrPartnerBitcoinPKH = 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));
+
+		// Bitcoin public key hash
+		assert dataByteBuffer.position() == addrBitcoinPublicKeyHash * MachineState.VALUE_SIZE : "addrBitcoinPublicKeyHash incorrect";
+		dataByteBuffer.put(Bytes.ensureCapacity(bitcoinPublicKeyHash, 32, 0));
+
+		// Redeem Qort amount
+		assert dataByteBuffer.position() == addrQortAmount * MachineState.VALUE_SIZE : "addrQortAmount incorrect";
+		dataByteBuffer.putLong(qortAmount);
+
+		// Expected Bitcoin amount
+		assert dataByteBuffer.position() == addrBitcoinAmount * MachineState.VALUE_SIZE : "addrBitcoinAmount incorrect";
+		dataByteBuffer.putLong(bitcoinAmount);
+
+		// 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 Bitcoin PKH
+		assert dataByteBuffer.position() == addrTradeMessagePartnerBitcoinPKHOffset * MachineState.VALUE_SIZE : "addrTradeMessagePartnerBitcoinPKHOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Index into data segment of partner's Bitcoin PKH, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerBitcoinPKHPointer * MachineState.VALUE_SIZE : "addrPartnerBitcoinPKHPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerBitcoinPKH);
+
+		// Offset into 'trade' MESSAGE data payload for extracting hash-of-secret-A
+		assert dataByteBuffer.position() == addrTradeMessageHashOfSecretAOffset * MachineState.VALUE_SIZE : "addrTradeMessageHashOfSecretAOffset incorrect";
+		dataByteBuffer.putLong(64L);
+
+		// Index into data segment to hash of secret A, used by GET_B_IND
+		assert dataByteBuffer.position() == addrHashOfSecretAPointer * MachineState.VALUE_SIZE : "addrHashOfSecretAPointer incorrect";
+		dataByteBuffer.putLong(addrHashOfSecretA);
+
+		// Offset into 'redeem' MESSAGE data payload for extracting Qortal receiving address
+		assert dataByteBuffer.position() == addrRedeemMessageReceivingAddressOffset * MachineState.VALUE_SIZE : "addrRedeemMessageReceivingAddressOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Source location and length for hashing any passed secret
+		assert dataByteBuffer.position() == addrMessageDataPointer * MachineState.VALUE_SIZE : "addrMessageDataPointer incorrect";
+		dataByteBuffer.putLong(addrMessageData);
+		assert dataByteBuffer.position() == addrMessageDataLength * MachineState.VALUE_SIZE : "addrMessageDataLength incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Pointer into data segment of where to save partner's receiving Qortal address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerReceivingAddressPointer * MachineState.VALUE_SIZE : "addrPartnerReceivingAddressPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerReceivingAddress);
+
+		assert dataByteBuffer.position() == addrEndOfConstants * MachineState.VALUE_SIZE : "dataByteBuffer position not at end of constants";
+
+		// Code labels
+		Integer labelRefund = null;
+
+		Integer labelTradeTxnLoop = null;
+		Integer labelCheckTradeTxn = null;
+		Integer labelCheckCancelTxn = null;
+		Integer labelNotTradeNorCancelTxn = null;
+		Integer labelCheckNonRefundTradeTxn = null;
+		Integer labelTradeTxnExtract = null;
+		Integer labelRedeemTxnLoop = null;
+		Integer labelCheckRedeemTxn = null;
+		Integer labelCheckRedeemTxnSender = null;
+		Integer labelPayout = null;
+
+		ByteBuffer codeByteBuffer = ByteBuffer.allocate(768);
+
+		// Two-pass version
+		for (int pass = 0; pass < 2; ++pass) {
+			codeByteBuffer.clear();
+
+			try {
+				/* Initialization */
+
+				// Use AT creation 'timestamp' as starting point for finding transactions sent to AT
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_CREATION_TIMESTAMP, addrLastTxnTimestamp));
+
+				// Load B register with AT creator's address so we can save it into addrCreatorAddress1-4
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_CREATOR_INTO_B));
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrCreatorAddressPointer));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for message from AT creator's trade address containing trade partner details, or AT owner's address to cancel offer */
+
+				/* Transaction processing loop */
+				labelTradeTxnLoop = codeByteBuffer.position();
+
+				/* Sleep until message arrives */
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.SLEEP_UNTIL_MESSAGE.value, addrLastTxnTimestamp));
+
+				// Find next transaction (if any) to this AT since the last one (referenced by addrLastTxnTimestamp)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrResult to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckTradeTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckTradeTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelTradeTxnLoop)));
+
+				/* Check transaction's sender. We're expecting AT creator's trade address for 'trade' message, or AT creator's own address for 'cancel' message. */
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of message sender's address with AT creator's trade address. If they don't match, check for cancel situation.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorTradeAddress1, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorTradeAddress2, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorTradeAddress3, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorTradeAddress4, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				// Message sender's address matches AT creator's trade address so go process 'trade' message
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelCheckNonRefundTradeTxn == null ? 0 : labelCheckNonRefundTradeTxn));
+
+				/* Checking message sender for possible cancel message */
+				labelCheckCancelTxn = codeByteBuffer.position();
+
+				// Compare each part of message sender's address with AT creator's address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorAddress1, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorAddress2, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorAddress3, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorAddress4, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				// Partner address is AT creator's address, so cancel offer and finish.
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.CANCELLED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				/* Not trade nor cancel message */
+				labelNotTradeNorCancelTxn = codeByteBuffer.position();
+
+				// Loop to find another transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Possible switch-to-trade-mode message */
+				labelCheckNonRefundTradeTxn = codeByteBuffer.position();
+
+				// Check 'trade' message we received has expected number of message bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to info extraction code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedTradeMessageLength, calcOffset(codeByteBuffer, labelTradeTxnExtract)));
+				// Message length didn't match - go back to finding another 'trade' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Extracting info from 'trade' MESSAGE transaction */
+				labelTradeTxnExtract = codeByteBuffer.position();
+
+				// Extract message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrQortalPartnerAddress1 (as pointed to by addrQortalPartnerAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrQortalPartnerAddressPointer));
+
+				// Extract trade partner's Bitcoin 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, addrTradeMessagePartnerBitcoinPKHOffset));
+				// Store partner's Bitcoin PKH (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerBitcoinPKHPointer));
+				// 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();
+
+				/* NOP - to ensure BITCOIN ACCT is unique */
+				codeByteBuffer.put(OpCode.NOP.compile());
+
+				// 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 BTC-QORT ACCT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		assert Arrays.equals(Crypto.digest(codeBytes), BitcoinACCTv3.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.BITCOIN.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 Bitcoin/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 BTC 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 Bitcoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Bitcoin 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 Bitcoin PKH
+		byte[] partnerBitcoinPKH = new byte[20];
+		dataByteBuffer.get(partnerBitcoinPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerBitcoinPKH.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 = partnerBitcoinPKH;
+			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.partnerBitcoinPKH = Arrays.copyOfRange(messageData, 0, 20);
+		offerMessageData.hashOfSecretA = Arrays.copyOfRange(messageData, 20, 40);
+		offerMessageData.lockTimeA = BitTwiddling.longFromBEBytes(messageData, 40);
+
+		return offerMessageData;
+	}
+
+	/** Returns 'trade' MESSAGE payload for AT creator to send to AT. */
+	public static byte[] buildTradeMessage(String partnerQortalTradeAddress, byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA, int refundTimeout) {
+		byte[] data = new byte[TRADE_MESSAGE_LENGTH];
+		byte[] partnerQortalAddressBytes = Base58.decode(partnerQortalTradeAddress);
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		byte[] refundTimeoutBytes = BitTwiddling.toBEByteArray((long) refundTimeout);
+
+		System.arraycopy(partnerQortalAddressBytes, 0, data, 0, partnerQortalAddressBytes.length);
+		System.arraycopy(partnerBitcoinPKH, 0, data, 32, partnerBitcoinPKH.length);
+		System.arraycopy(refundTimeoutBytes, 0, data, 56, refundTimeoutBytes.length);
+		System.arraycopy(hashOfSecretA, 0, data, 64, hashOfSecretA.length);
+		System.arraycopy(lockTimeABytes, 0, data, 88, lockTimeABytes.length);
+
+		return data;
+	}
+
+	/** Returns 'cancel' MESSAGE payload for AT creator to cancel trade AT. */
+	@Override
+	public byte[] buildCancelMessage(String creatorQortalAddress) {
+		byte[] data = new byte[CANCEL_MESSAGE_LENGTH];
+		byte[] creatorQortalAddressBytes = Base58.decode(creatorQortalAddress);
+
+		System.arraycopy(creatorQortalAddressBytes, 0, data, 0, creatorQortalAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns 'redeem' MESSAGE payload for trade partner to send to AT. */
+	public static byte[] buildRedeemMessage(byte[] secretA, String qortalReceivingAddress) {
+		byte[] data = new byte[REDEEM_MESSAGE_LENGTH];
+		byte[] qortalReceivingAddressBytes = Base58.decode(qortalReceivingAddress);
+
+		System.arraycopy(secretA, 0, data, 0, secretA.length);
+		System.arraycopy(qortalReceivingAddressBytes, 0, data, 32, qortalReceivingAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns refund timeout (minutes) based on trade partner's 'offer' MESSAGE timestamp and P2SH-A locktime. */
+	public static int calcRefundTimeout(long offerMessageTimestamp, int lockTimeA) {
+		// refund should be triggered halfway between offerMessageTimestamp and lockTimeA
+		return (int) ((lockTimeA - (offerMessageTimestamp / 1000L)) / 2L / 60L);
+	}
+
+	@Override
+	public byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+		String atAddress = crossChainTradeData.qortalAtAddress;
+		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
+
+		// We don't have partner's public key so we check every message to AT
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, atAddress, null, null, null);
+		if (messageTransactionsData == null)
+			return null;
+
+		// Find 'redeem' message
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			// Check message payload type/encryption
+			if (messageTransactionData.isText() || messageTransactionData.isEncrypted())
+				continue;
+
+			// Check message payload size
+			byte[] messageData = messageTransactionData.getData();
+			if (messageData.length != REDEEM_MESSAGE_LENGTH)
+				// Wrong payload length
+				continue;
+
+			// Check sender
+			if (!Crypto.toAddress(messageTransactionData.getSenderPublicKey()).equals(redeemerAddress))
+				// Wrong sender;
+				continue;
+
+			// Extract secretA
+			byte[] secretA = new byte[32];
+			System.arraycopy(messageData, 0, secretA, 0, secretA.length);
+
+			byte[] hashOfSecretA = Crypto.hash160(secretA);
+			if (!Arrays.equals(hashOfSecretA, crossChainTradeData.hashOfSecretA))
+				continue;
+
+			return secretA;
+		}
+
+		return null;
+	}
+
+}

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

@@ -13,8 +13,8 @@ import org.qortal.utils.Triple;
 public enum SupportedBlockchain {
 
 	BITCOIN(Arrays.asList(
-				Triple.valueOf(BitcoinACCTv1.NAME, BitcoinACCTv1.CODE_BYTES_HASH, BitcoinACCTv1::getInstance)
-				// Could add improved BitcoinACCTv2 here in the future
+				Triple.valueOf(BitcoinACCTv1.NAME, BitcoinACCTv1.CODE_BYTES_HASH, BitcoinACCTv1::getInstance),
+				Triple.valueOf(BitcoinACCTv3.NAME, BitcoinACCTv3.CODE_BYTES_HASH, BitcoinACCTv3::getInstance)
 			)) {
 		@Override
 		public ForeignBlockchain getInstance() {
@@ -23,7 +23,7 @@ public enum SupportedBlockchain {
 
 		@Override
 		public ACCT getLatestAcct() {
-			return BitcoinACCTv1.getInstance();
+			return BitcoinACCTv3.getInstance();
 		}
 	},
 

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

@@ -23,6 +23,7 @@ import java.util.List;
 
 import javax.swing.JDialog;
 import javax.swing.JMenuItem;
+import javax.swing.JOptionPane;
 import javax.swing.JPopupMenu;
 import javax.swing.SwingWorker;
 import javax.swing.event.PopupMenuEvent;
@@ -178,6 +179,14 @@ public class SysTray {
 			menu.add(syncTime);
 		}
 
+		JMenuItem about = new JMenuItem(Translator.INSTANCE.translate("SysTray", "BUILD_VERSION"));
+		about.addActionListener(actionEvent -> {
+			destroyHiddenDialog();
+
+			JOptionPane.showMessageDialog(null,"Qortal Core\n" + Translator.INSTANCE.translate("SysTray", "BUILD_VERSION") + ":\n" + Controller.getInstance().getVersionStringWithoutPrefix(),"Qortal Core",1);
+		});
+		menu.add(about);
+
 		JMenuItem exit = new JMenuItem(Translator.INSTANCE.translate("SysTray", "EXIT"));
 		exit.addActionListener(actionEvent -> {
 			destroyHiddenDialog();

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

@@ -12,6 +12,7 @@ import org.qortal.data.network.PeerData;
 import org.qortal.network.message.ChallengeMessage;
 import org.qortal.network.message.Message;
 import org.qortal.network.message.MessageException;
+import org.qortal.network.message.MessageType;
 import org.qortal.network.task.MessageTask;
 import org.qortal.network.task.PingTask;
 import org.qortal.settings.Settings;
@@ -546,6 +547,10 @@ public class Peer {
                     // adjusting position accordingly, reset limit to capacity
                     this.byteBuffer.compact();
 
+                    // Unsupported message type? Discard with no further processing
+                    if (message.getType() == MessageType.UNSUPPORTED)
+                        continue;
+
                     BlockingQueue<Message> queue = this.replyQueues.get(message.getId());
                     if (queue != null) {
                         // Adding message to queue will unblock thread waiting for response

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

@@ -9,6 +9,7 @@ import org.qortal.data.at.ATStateData;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformation;
 import org.qortal.transform.block.BlockTransformer;
 import org.qortal.utils.Triple;
 
@@ -46,12 +47,12 @@ public class BlockMessage extends Message {
 		try {
 			int height = byteBuffer.getInt();
 
-			Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = BlockTransformer.fromByteBuffer(byteBuffer);
+			BlockTransformation blockTransformation = BlockTransformer.fromByteBuffer(byteBuffer);
 
-			BlockData blockData = blockInfo.getA();
+			BlockData blockData = blockTransformation.getBlockData();
 			blockData.setHeight(height);
 
-			return new BlockMessage(id, blockData, blockInfo.getB(), blockInfo.getC());
+			return new BlockMessage(id, blockData, blockTransformation.getTransactions(), blockTransformation.getAtStates());
 		} catch (TransformationException e) {
 			LOGGER.info(String.format("Received garbled BLOCK message: %s", e.getMessage()));
 			throw new MessageException(e.getMessage(), e);

src/main/java/org/qortal/network/message/BlockV2Message.java

@@ -0,0 +1,87 @@
+package org.qortal.network.message;
+
+import com.google.common.primitives.Ints;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.block.Block;
+import org.qortal.data.block.BlockData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformation;
+import org.qortal.transform.block.BlockTransformer;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.List;
+
+public class BlockV2Message extends Message {
+
+	private static final Logger LOGGER = LogManager.getLogger(BlockV2Message.class);
+	public static final long MIN_PEER_VERSION = 0x300030003L; // 3.3.3
+
+	private BlockData blockData;
+	private List<TransactionData> transactions;
+	private byte[] atStatesHash;
+
+	public BlockV2Message(Block block) throws TransformationException {
+		super(MessageType.BLOCK_V2);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(block.getBlockData().getHeight()));
+
+			bytes.write(BlockTransformer.toBytesV2(block));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
+
+	public BlockV2Message(byte[] cachedBytes) {
+		super(MessageType.BLOCK_V2);
+
+		this.dataBytes = cachedBytes;
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
+
+	private BlockV2Message(int id, BlockData blockData, List<TransactionData> transactions, byte[] atStatesHash) {
+		super(id, MessageType.BLOCK_V2);
+
+		this.blockData = blockData;
+		this.transactions = transactions;
+		this.atStatesHash = atStatesHash;
+	}
+
+	public BlockData getBlockData() {
+		return this.blockData;
+	}
+
+	public List<TransactionData> getTransactions() {
+		return this.transactions;
+	}
+
+	public byte[] getAtStatesHash() {
+		return this.atStatesHash;
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+		try {
+			int height = byteBuffer.getInt();
+
+			BlockTransformation blockTransformation = BlockTransformer.fromByteBufferV2(byteBuffer);
+
+			BlockData blockData = blockTransformation.getBlockData();
+			blockData.setHeight(height);
+
+			return new BlockV2Message(id, blockData, blockTransformation.getTransactions(), blockTransformation.getAtStatesHash());
+		} catch (TransformationException e) {
+			LOGGER.info(String.format("Received garbled BLOCK_V2 message: %s", e.getMessage()));
+			throw new MessageException(e.getMessage(), e);
+		}
+	}
+
+}

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

@@ -103,8 +103,7 @@ public abstract class Message {
 			int typeValue = readOnlyBuffer.getInt();
 			MessageType messageType = MessageType.valueOf(typeValue);
 			if (messageType == null)
-				// Unrecognised message type
-				throw new MessageException(String.format("Received unknown message type [%d]", typeValue));
+				messageType = MessageType.UNSUPPORTED;
 
 			// Optional message ID
 			byte hasId = readOnlyBuffer.get();

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

@@ -8,6 +8,9 @@ import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.toMap;
 
 public enum MessageType {
+    // Pseudo-message, not sent over the wire
+    UNSUPPORTED(-1, UnsupportedMessage::fromByteBuffer),
+
     // Handshaking
     HELLO(0, HelloMessage::fromByteBuffer),
     GOODBYE(1, GoodbyeMessage::fromByteBuffer),
@@ -31,6 +34,7 @@ public enum MessageType {
 
     BLOCK(50, BlockMessage::fromByteBuffer),
     GET_BLOCK(51, GetBlockMessage::fromByteBuffer),
+    BLOCK_V2(52, BlockV2Message::fromByteBuffer),
 
     SIGNATURES(60, SignaturesMessage::fromByteBuffer),
     GET_SIGNATURES_V2(61, GetSignaturesV2Message::fromByteBuffer),

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

@@ -0,0 +1,20 @@
+package org.qortal.network.message;
+
+import java.nio.ByteBuffer;
+
+public class UnsupportedMessage extends Message {
+
+	public UnsupportedMessage() {
+		super(MessageType.UNSUPPORTED);
+		throw new UnsupportedOperationException("Unsupported message is unsupported!");
+	}
+
+	private UnsupportedMessage(int id) {
+		super(id, MessageType.UNSUPPORTED);
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) throws MessageException {
+		return new UnsupportedMessage(id);
+	}
+
+}

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

@@ -9,6 +9,7 @@ import org.qortal.data.block.BlockData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.settings.Settings;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformation;
 import org.qortal.transform.block.BlockTransformer;
 import org.qortal.utils.Triple;
 
@@ -66,7 +67,7 @@ public class BlockArchiveReader {
         this.fileListCache = Map.copyOf(map);
     }
 
-    public Triple<BlockData, List<TransactionData>, List<ATStateData>> fetchBlockAtHeight(int height) {
+    public BlockTransformation fetchBlockAtHeight(int height) {
         if (this.fileListCache == null) {
             this.fetchFileList();
         }
@@ -77,13 +78,13 @@ public class BlockArchiveReader {
         }
 
         ByteBuffer byteBuffer = ByteBuffer.wrap(serializedBytes);
-        Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = null;
+        BlockTransformation blockInfo = null;
         try {
             blockInfo = BlockTransformer.fromByteBuffer(byteBuffer);
-            if (blockInfo != null && blockInfo.getA() != null) {
+            if (blockInfo != null && blockInfo.getBlockData() != null) {
                 // Block height is stored outside of the main serialized bytes, so it
                 // won't be set automatically.
-                blockInfo.getA().setHeight(height);
+                blockInfo.getBlockData().setHeight(height);
             }
         } catch (TransformationException e) {
             return null;
@@ -91,8 +92,7 @@ public class BlockArchiveReader {
         return blockInfo;
     }
 
-    public Triple<BlockData, List<TransactionData>, List<ATStateData>> fetchBlockWithSignature(
-            byte[] signature, Repository repository) {
+    public BlockTransformation fetchBlockWithSignature(byte[] signature, Repository repository) {
 
         if (this.fileListCache == null) {
             this.fetchFileList();
@@ -105,13 +105,12 @@ public class BlockArchiveReader {
         return null;
     }
 
-    public List<Triple<BlockData, List<TransactionData>, List<ATStateData>>> fetchBlocksFromRange(
-            int startHeight, int endHeight) {
+    public List<BlockTransformation> fetchBlocksFromRange(int startHeight, int endHeight) {
 
-        List<Triple<BlockData, List<TransactionData>, List<ATStateData>>> blockInfoList = new ArrayList<>();
+        List<BlockTransformation> blockInfoList = new ArrayList<>();
 
         for (int height = startHeight; height <= endHeight; height++) {
-            Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = this.fetchBlockAtHeight(height);
+            BlockTransformation blockInfo = this.fetchBlockAtHeight(height);
             if (blockInfo == null) {
                 return blockInfoList;
             }

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

@@ -1,16 +1,13 @@
 package org.qortal.repository.hsqldb;
 
-import org.qortal.api.ApiError;
-import org.qortal.api.ApiExceptionFactory;
 import org.qortal.api.model.BlockSignerSummary;
-import org.qortal.block.Block;
 import org.qortal.data.block.BlockArchiveData;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.block.BlockSummaryData;
 import org.qortal.repository.BlockArchiveReader;
 import org.qortal.repository.BlockArchiveRepository;
 import org.qortal.repository.DataException;
-import org.qortal.utils.Triple;
+import org.qortal.transform.block.BlockTransformation;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -29,11 +26,11 @@ public class HSQLDBBlockArchiveRepository implements BlockArchiveRepository {
 
     @Override
     public BlockData fromSignature(byte[] signature) throws DataException {
-        Triple blockInfo = BlockArchiveReader.getInstance().fetchBlockWithSignature(signature, this.repository);
-        if (blockInfo != null) {
-            return (BlockData) blockInfo.getA();
-        }
-        return null;
+        BlockTransformation blockInfo = BlockArchiveReader.getInstance().fetchBlockWithSignature(signature, this.repository);
+        if (blockInfo == null)
+            return null;
+
+        return blockInfo.getBlockData();
     }
 
     @Override
@@ -47,11 +44,11 @@ public class HSQLDBBlockArchiveRepository implements BlockArchiveRepository {
 
     @Override
     public BlockData fromHeight(int height) throws DataException {
-        Triple blockInfo = BlockArchiveReader.getInstance().fetchBlockAtHeight(height);
-        if (blockInfo != null) {
-            return (BlockData) blockInfo.getA();
-        }
-        return null;
+        BlockTransformation blockInfo = BlockArchiveReader.getInstance().fetchBlockAtHeight(height);
+        if (blockInfo == null)
+            return null;
+
+        return blockInfo.getBlockData();
     }
 
     @Override
@@ -79,9 +76,9 @@ public class HSQLDBBlockArchiveRepository implements BlockArchiveRepository {
             int height = referenceBlock.getHeight();
             if (height > 0) {
                 // Request the block at height + 1
-                Triple blockInfo = BlockArchiveReader.getInstance().fetchBlockAtHeight(height + 1);
+                BlockTransformation blockInfo = BlockArchiveReader.getInstance().fetchBlockAtHeight(height + 1);
                 if (blockInfo != null) {
-                    return (BlockData) blockInfo.getA();
+                    return blockInfo.getBlockData();
                 }
             }
         }

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

@@ -964,6 +964,11 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("DROP TABLE ArbitraryPeers");
 					break;
 
+				case 42:
+					// We need more space for online accounts
+					stmt.execute("ALTER TABLE Blocks ALTER COLUMN online_accounts SET DATA TYPE VARBINARY(10240)");
+					break;
+
 				default:
 					// nothing to do
 					return false;

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

@@ -6,6 +6,7 @@ import java.util.Objects;
 import java.util.stream.Collectors;
 
 import org.qortal.account.Account;
+import org.qortal.block.BlockChain;
 import org.qortal.controller.arbitrary.ArbitraryDataManager;
 import org.qortal.controller.arbitrary.ArbitraryDataStorageManager;
 import org.qortal.crypto.Crypto;
@@ -19,6 +20,7 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.arbitrary.ArbitraryDataFile;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.ArbitraryTransactionTransformer;
 import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.ArbitraryTransactionUtils;
@@ -86,6 +88,14 @@ public class ArbitraryTransaction extends Transaction {
 	@Override
 	public boolean hasValidReference() throws DataException {
 		// We shouldn't really get this far, but just in case:
+
+		// Disable reference checking after feature trigger timestamp
+		if (this.arbitraryTransactionData.getTimestamp() >= BlockChain.getInstance().getDisableReferenceTimestamp()) {
+			// Allow any value as long as it is the correct length
+			return this.arbitraryTransactionData.getReference() != null &&
+					this.arbitraryTransactionData.getReference().length == Transformer.SIGNATURE_LENGTH;
+		}
+
 		if (this.arbitraryTransactionData.getReference() == null) {
 			return false;
 		}

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

@@ -5,6 +5,7 @@ import java.util.List;
 
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
+import org.qortal.block.BlockChain;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.asset.AssetData;
 import org.qortal.data.transaction.ATTransactionData;
@@ -12,6 +13,7 @@ import org.qortal.data.transaction.TransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.AtTransactionTransformer;
 import org.qortal.utils.Amounts;
 
@@ -75,6 +77,13 @@ public class AtTransaction extends Transaction {
 
 	@Override
 	public boolean hasValidReference() throws DataException {
+		// Disable reference checking after feature trigger timestamp
+		if (this.atTransactionData.getTimestamp() >= BlockChain.getInstance().getDisableReferenceTimestamp()) {
+			// Allow any value as long as it is the correct length
+			return this.atTransactionData.getReference() != null &&
+					this.atTransactionData.getReference().length == Transformer.SIGNATURE_LENGTH;
+		}
+
 		// Check reference is correct, using AT account, not transaction creator which is null account
 		Account atAccount = getATAccount();
 		return Arrays.equals(atAccount.getLastReference(), atTransactionData.getReference());

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

@@ -8,6 +8,7 @@ import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.account.PublicKeyAccount;
 import org.qortal.asset.Asset;
+import org.qortal.block.BlockChain;
 import org.qortal.crypto.Crypto;
 import org.qortal.crypto.MemoryPoW;
 import org.qortal.data.PaymentData;
@@ -20,6 +21,7 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.GroupRepository;
 import org.qortal.repository.Repository;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.ChatTransactionTransformer;
 import org.qortal.transform.transaction.MessageTransactionTransformer;
 import org.qortal.transform.transaction.TransactionTransformer;
@@ -163,6 +165,14 @@ public class MessageTransaction extends Transaction {
 	@Override
 	public boolean hasValidReference() throws DataException {
 		// We shouldn't really get this far, but just in case:
+
+		// Disable reference checking after feature trigger timestamp
+		if (this.messageTransactionData.getTimestamp() >= BlockChain.getInstance().getDisableReferenceTimestamp()) {
+			// Allow any value as long as it is the correct length
+			return this.messageTransactionData.getReference() != null &&
+					this.messageTransactionData.getReference().length == Transformer.SIGNATURE_LENGTH;
+		}
+
 		if (this.messageTransactionData.getReference() == null)
 			return false;
 

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

@@ -31,6 +31,7 @@ import org.qortal.repository.GroupRepository;
 import org.qortal.repository.Repository;
 import org.qortal.settings.Settings;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.NTP;
 
@@ -905,6 +906,13 @@ public abstract class Transaction {
 	 * @throws DataException
 	 */
 	public boolean hasValidReference() throws DataException {
+		// Disable reference checking after feature trigger timestamp
+		if (this.transactionData.getTimestamp() >= BlockChain.getInstance().getDisableReferenceTimestamp()) {
+			// Allow any value as long as it is the correct length
+			return this.transactionData.getReference() != null &&
+					this.transactionData.getReference().length == Transformer.SIGNATURE_LENGTH;
+		}
+
 		Account creator = getCreator();
 
 		return Arrays.equals(transactionData.getReference(), creator.getLastReference());

src/main/java/org/qortal/transform/block/BlockTransformation.java

@@ -0,0 +1,44 @@
+package org.qortal.transform.block;
+
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.block.BlockData;
+import org.qortal.data.transaction.TransactionData;
+
+import java.util.List;
+
+public class BlockTransformation {
+    private final BlockData blockData;
+    private final List<TransactionData> transactions;
+    private final List<ATStateData> atStates;
+    private final byte[] atStatesHash;
+
+    /*package*/ BlockTransformation(BlockData blockData, List<TransactionData> transactions, List<ATStateData> atStates) {
+        this.blockData = blockData;
+        this.transactions = transactions;
+        this.atStates = atStates;
+        this.atStatesHash = null;
+    }
+
+    /*package*/ BlockTransformation(BlockData blockData, List<TransactionData> transactions, byte[] atStatesHash) {
+        this.blockData = blockData;
+        this.transactions = transactions;
+        this.atStates = null;
+        this.atStatesHash = atStatesHash;
+    }
+
+    public BlockData getBlockData() {
+        return blockData;
+    }
+
+    public List<TransactionData> getTransactions() {
+        return transactions;
+    }
+
+    public List<ATStateData> getAtStates() {
+        return atStates;
+    }
+
+    public byte[] getAtStatesHash() {
+        return atStatesHash;
+    }
+}

src/main/java/org/qortal/transform/block/BlockTransformer.java

@@ -3,12 +3,14 @@ package org.qortal.transform.block;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import org.qortal.block.Block;
 import org.qortal.block.BlockChain;
+import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATStateData;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.transaction.TransactionData;
@@ -20,7 +22,6 @@ import org.qortal.transform.Transformer;
 import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.Base58;
 import org.qortal.utils.Serialization;
-import org.qortal.utils.Triple;
 
 import com.google.common.primitives.Ints;
 import com.google.common.primitives.Longs;
@@ -45,14 +46,13 @@ public class BlockTransformer extends Transformer {
 
 	protected static final int AT_BYTES_LENGTH = INT_LENGTH;
 	protected static final int AT_FEES_LENGTH = AMOUNT_LENGTH;
-	protected static final int AT_LENGTH = AT_FEES_LENGTH + AT_BYTES_LENGTH;
 
 	protected static final int ONLINE_ACCOUNTS_COUNT_LENGTH = INT_LENGTH;
 	protected static final int ONLINE_ACCOUNTS_SIZE_LENGTH = INT_LENGTH;
 	protected static final int ONLINE_ACCOUNTS_TIMESTAMP_LENGTH = TIMESTAMP_LENGTH;
 	protected static final int ONLINE_ACCOUNTS_SIGNATURES_COUNT_LENGTH = INT_LENGTH;
 
-	protected static final int AT_ENTRY_LENGTH = ADDRESS_LENGTH + SHA256_LENGTH + AMOUNT_LENGTH;
+	public static final int AT_ENTRY_LENGTH = ADDRESS_LENGTH + SHA256_LENGTH + AMOUNT_LENGTH;
 
 	/**
 	 * Extract block data and transaction data from serialized bytes.
@@ -61,7 +61,7 @@ public class BlockTransformer extends Transformer {
 	 * @return BlockData and a List of transactions.
 	 * @throws TransformationException
 	 */
-	public static Triple<BlockData, List<TransactionData>, List<ATStateData>> fromBytes(byte[] bytes) throws TransformationException {
+	public static BlockTransformation fromBytes(byte[] bytes) throws TransformationException {
 		if (bytes == null)
 			return null;
 
@@ -76,28 +76,40 @@ public class BlockTransformer extends Transformer {
 	/**
 	 * Extract block data and transaction data from serialized bytes containing a single block.
 	 *
-	 * @param bytes
+	 * @param byteBuffer source of serialized block bytes
 	 * @return BlockData and a List of transactions.
 	 * @throws TransformationException
 	 */
-	public static Triple<BlockData, List<TransactionData>, List<ATStateData>> fromByteBuffer(ByteBuffer byteBuffer) throws TransformationException {
+	public static BlockTransformation fromByteBuffer(ByteBuffer byteBuffer) throws TransformationException {
+		return BlockTransformer.fromByteBuffer(byteBuffer, false);
+	}
+
+	/**
+	 * Extract block data and transaction data from serialized bytes containing a single block.
+	 *
+	 * @param byteBuffer source of serialized block bytes
+	 * @return BlockData and a List of transactions.
+	 * @throws TransformationException
+	 */
+	public static BlockTransformation fromByteBufferV2(ByteBuffer byteBuffer) throws TransformationException {
 		return BlockTransformer.fromByteBuffer(byteBuffer, true);
 	}
 
 	/**
-	 * Extract block data and transaction data from serialized bytes containing one or more blocks.
-	 * 
-	 * @param bytes
+	 * Extract block data and transaction data from serialized bytes containing a single block, in one of two forms.
+	 *
+	 * @param byteBuffer source of serialized block bytes
+	 * @param isV2 set to true if AT state info is represented by a single hash, false if serialized as per-AT address+state hash+fees
 	 * @return the next block's BlockData and a List of transactions.
 	 * @throws TransformationException
 	 */
-	public static Triple<BlockData, List<TransactionData>, List<ATStateData>> fromByteBuffer(ByteBuffer byteBuffer, boolean finalBlockInBuffer) throws TransformationException {
+	private static BlockTransformation fromByteBuffer(ByteBuffer byteBuffer, boolean isV2) throws TransformationException {
 		int version = byteBuffer.getInt();
 
-		if (finalBlockInBuffer && byteBuffer.remaining() < BASE_LENGTH + AT_BYTES_LENGTH - VERSION_LENGTH)
+		if (byteBuffer.remaining() < BASE_LENGTH + AT_BYTES_LENGTH - VERSION_LENGTH)
 			throw new TransformationException("Byte data too short for Block");
 
-		if (finalBlockInBuffer && byteBuffer.remaining() > BlockChain.getInstance().getMaxBlockSize())
+		if (byteBuffer.remaining() > BlockChain.getInstance().getMaxBlockSize())
 			throw new TransformationException("Byte data too long for Block");
 
 		long timestamp = byteBuffer.getLong();
@@ -117,42 +129,52 @@ public class BlockTransformer extends Transformer {
 
 		int atCount = 0;
 		long atFees = 0;
-		List<ATStateData> atStates = new ArrayList<>();
+		byte[] atStatesHash = null;
+		List<ATStateData> atStates = null;
 
-		int atBytesLength = byteBuffer.getInt();
+		if (isV2) {
+			// Simply: AT count, AT total fees, hash(all AT states)
+			atCount = byteBuffer.getInt();
+			atFees = byteBuffer.getLong();
+			atStatesHash = new byte[Transformer.SHA256_LENGTH];
+			byteBuffer.get(atStatesHash);
+		} else {
+			// V1: AT info byte length, then per-AT entries of AT address + state hash + fees
+			int atBytesLength = byteBuffer.getInt();
+			if (atBytesLength > BlockChain.getInstance().getMaxBlockSize())
+				throw new TransformationException("Byte data too long for Block's AT info");
 
-		if (atBytesLength > BlockChain.getInstance().getMaxBlockSize())
-			throw new TransformationException("Byte data too long for Block's AT info");
+			// Read AT-address, SHA256 hash and fees
+			if (atBytesLength % AT_ENTRY_LENGTH != 0)
+				throw new TransformationException("AT byte data not a multiple of AT entry length");
 
-		ByteBuffer atByteBuffer = byteBuffer.slice();
-		atByteBuffer.limit(atBytesLength);
+			ByteBuffer atByteBuffer = byteBuffer.slice();
+			atByteBuffer.limit(atBytesLength);
 
-		// Read AT-address, SHA256 hash and fees
-		if (atBytesLength % AT_ENTRY_LENGTH != 0)
-			throw new TransformationException("AT byte data not a multiple of AT entry length");
+			atStates = new ArrayList<>();
+			while (atByteBuffer.hasRemaining()) {
+				byte[] atAddressBytes = new byte[ADDRESS_LENGTH];
+				atByteBuffer.get(atAddressBytes);
+				String atAddress = Base58.encode(atAddressBytes);
 
-		while (atByteBuffer.hasRemaining()) {
-			byte[] atAddressBytes = new byte[ADDRESS_LENGTH];
-			atByteBuffer.get(atAddressBytes);
-			String atAddress = Base58.encode(atAddressBytes);
+				byte[] stateHash = new byte[SHA256_LENGTH];
+				atByteBuffer.get(stateHash);
 
-			byte[] stateHash = new byte[SHA256_LENGTH];
-			atByteBuffer.get(stateHash);
+				long fees = atByteBuffer.getLong();
 
-			long fees = atByteBuffer.getLong();
+				// Add this AT's fees to our total
+				atFees += fees;
 
-			// Add this AT's fees to our total
-			atFees += fees;
+				atStates.add(new ATStateData(atAddress, stateHash, fees));
+			}
 
-			atStates.add(new ATStateData(atAddress, stateHash, fees));
+			// Bump byteBuffer over AT states just read in slice
+			byteBuffer.position(byteBuffer.position() + atBytesLength);
+
+			// AT count to reflect the number of states we have
+			atCount = atStates.size();
 		}
 
-		// Bump byteBuffer over AT states just read in slice
-		byteBuffer.position(byteBuffer.position() + atBytesLength);
-
-		// AT count to reflect the number of states we have
-		atCount = atStates.size();
-
 		// Add AT fees to totalFees
 		totalFees += atFees;
 
@@ -221,16 +243,15 @@ public class BlockTransformer extends Transformer {
 			byteBuffer.get(onlineAccountsSignatures);
 		}
 
-		// We should only complain about excess byte data if we aren't expecting more blocks in this ByteBuffer
-		if (finalBlockInBuffer && byteBuffer.hasRemaining())
-			throw new TransformationException("Excess byte data found after parsing Block");
-
 		// We don't have a height!
 		Integer height = null;
 		BlockData blockData = new BlockData(version, reference, transactionCount, totalFees, transactionsSignature, height, timestamp,
 				minterPublicKey, minterSignature, atCount, atFees, encodedOnlineAccounts, onlineAccountsCount, onlineAccountsTimestamp, onlineAccountsSignatures);
 
-		return new Triple<>(blockData, transactions, atStates);
+		if (isV2)
+			return new BlockTransformation(blockData, transactions, atStatesHash);
+		else
+			return new BlockTransformation(blockData, transactions, atStates);
 	}
 
 	public static int getDataLength(Block block) throws TransformationException {
@@ -266,6 +287,14 @@ public class BlockTransformer extends Transformer {
 	}
 
 	public static byte[] toBytes(Block block) throws TransformationException {
+		return toBytes(block, false);
+	}
+
+	public static byte[] toBytesV2(Block block) throws TransformationException {
+		return toBytes(block, true);
+	}
+
+	private static byte[] toBytes(Block block, boolean isV2) throws TransformationException {
 		BlockData blockData = block.getBlockData();
 
 		try {
@@ -279,16 +308,37 @@ public class BlockTransformer extends Transformer {
 			bytes.write(blockData.getMinterSignature());
 
 			int atBytesLength = blockData.getATCount() * AT_ENTRY_LENGTH;
-			bytes.write(Ints.toByteArray(atBytesLength));
+			if (isV2) {
+				ByteArrayOutputStream atHashBytes = new ByteArrayOutputStream(atBytesLength);
+				long atFees = 0;
 
-			for (ATStateData atStateData : block.getATStates()) {
-				// Skip initial states generated by DEPLOY_AT transactions in the same block
-				if (atStateData.isInitial())
-					continue;
+				for (ATStateData atStateData : block.getATStates()) {
+					// Skip initial states generated by DEPLOY_AT transactions in the same block
+					if (atStateData.isInitial())
+						continue;
 
-				bytes.write(Base58.decode(atStateData.getATAddress()));
-				bytes.write(atStateData.getStateHash());
-				bytes.write(Longs.toByteArray(atStateData.getFees()));
+					atHashBytes.write(atStateData.getATAddress().getBytes(StandardCharsets.UTF_8));
+					atHashBytes.write(atStateData.getStateHash());
+					atHashBytes.write(Longs.toByteArray(atStateData.getFees()));
+
+					atFees += atStateData.getFees();
+				}
+
+				bytes.write(Ints.toByteArray(blockData.getATCount()));
+				bytes.write(Longs.toByteArray(atFees));
+				bytes.write(Crypto.digest(atHashBytes.toByteArray()));
+			} else {
+				bytes.write(Ints.toByteArray(atBytesLength));
+
+				for (ATStateData atStateData : block.getATStates()) {
+					// Skip initial states generated by DEPLOY_AT transactions in the same block
+					if (atStateData.isInitial())
+						continue;
+
+					bytes.write(Base58.decode(atStateData.getATAddress()));
+					bytes.write(atStateData.getStateHash());
+					bytes.write(Longs.toByteArray(atStateData.getFees()));
+				}
 			}
 
 			// Transactions

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

@@ -6,6 +6,7 @@ import org.qortal.data.transaction.TransactionData;
 import org.qortal.repository.BlockArchiveReader;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.transform.block.BlockTransformation;
 
 import java.util.List;
 
@@ -33,8 +34,7 @@ public class BlockArchiveUtils {
         repository.discardChanges();
         final int requestedRange = endHeight+1-startHeight;
 
-        List<Triple<BlockData, List<TransactionData>, List<ATStateData>>> blockInfoList =
-                BlockArchiveReader.getInstance().fetchBlocksFromRange(startHeight, endHeight);
+        List<BlockTransformation> blockInfoList = BlockArchiveReader.getInstance().fetchBlocksFromRange(startHeight, endHeight);
 
         // Ensure that we have received all of the requested blocks
         if (blockInfoList == null || blockInfoList.isEmpty()) {
@@ -43,27 +43,26 @@ public class BlockArchiveUtils {
         if (blockInfoList.size() != requestedRange) {
             throw new IllegalStateException("Non matching block count when importing from archive");
         }
-        Triple<BlockData, List<TransactionData>, List<ATStateData>> firstBlock = blockInfoList.get(0);
-        if (firstBlock == null || firstBlock.getA().getHeight() != startHeight) {
+        BlockTransformation firstBlock = blockInfoList.get(0);
+        if (firstBlock == null || firstBlock.getBlockData().getHeight() != startHeight) {
             throw new IllegalStateException("Non matching first block when importing from archive");
         }
         if (blockInfoList.size() > 0) {
-            Triple<BlockData, List<TransactionData>, List<ATStateData>> lastBlock =
-                    blockInfoList.get(blockInfoList.size() - 1);
-            if (lastBlock == null || lastBlock.getA().getHeight() != endHeight) {
+            BlockTransformation lastBlock = blockInfoList.get(blockInfoList.size() - 1);
+            if (lastBlock == null || lastBlock.getBlockData().getHeight() != endHeight) {
                 throw new IllegalStateException("Non matching last block when importing from archive");
             }
         }
 
         // Everything seems okay, so go ahead with the import
-        for (Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo : blockInfoList) {
+        for (BlockTransformation blockInfo : blockInfoList) {
             try {
                 // Save block
-                repository.getBlockRepository().save(blockInfo.getA());
+                repository.getBlockRepository().save(blockInfo.getBlockData());
 
                 // Save AT state data hashes
-                for (ATStateData atStateData : blockInfo.getC()) {
-                    atStateData.setHeight(blockInfo.getA().getHeight());
+                for (ATStateData atStateData : blockInfo.getAtStates()) {
+                    atStateData.setHeight(blockInfo.getBlockData().getHeight());
                     repository.getATRepository().save(atStateData);
                 }
 

src/main/resources/blockchain.json

@@ -58,8 +58,10 @@
 		"newBlockSigHeight": 320000,
 		"shareBinFix": 399000,
 		"calcChainWeightTimestamp": 1620579600000,
+		"newConsensusTimestamp": 9999999999999,
 		"transactionV5Timestamp": 1642176000000,
-		"transactionV6Timestamp": 9999999999999
+		"transactionV6Timestamp": 9999999999999,
+		"disableReferenceTimestamp": 1655222400000
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/java/org/qortal/test/BlockArchiveTests.java

@@ -20,6 +20,7 @@ import org.qortal.test.common.Common;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.Transaction;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformation;
 import org.qortal.utils.BlockArchiveUtils;
 import org.qortal.utils.NTP;
 import org.qortal.utils.Triple;
@@ -123,8 +124,8 @@ public class BlockArchiveTests extends Common {
 
 			// Read block 2 from the archive
 			BlockArchiveReader reader = BlockArchiveReader.getInstance();
-			Triple<BlockData, List<TransactionData>, List<ATStateData>> block2Info = reader.fetchBlockAtHeight(2);
-			BlockData block2ArchiveData = block2Info.getA();
+			BlockTransformation block2Info = reader.fetchBlockAtHeight(2);
+			BlockData block2ArchiveData = block2Info.getBlockData();
 
 			// Read block 2 from the repository
 			BlockData block2RepositoryData = repository.getBlockRepository().fromHeight(2);
@@ -137,8 +138,8 @@ public class BlockArchiveTests extends Common {
 			assertEquals(1, block2ArchiveData.getOnlineAccountsCount());
 
 			// Read block 900 from the archive
-			Triple<BlockData, List<TransactionData>, List<ATStateData>> block900Info = reader.fetchBlockAtHeight(900);
-			BlockData block900ArchiveData = block900Info.getA();
+			BlockTransformation block900Info = reader.fetchBlockAtHeight(900);
+			BlockData block900ArchiveData = block900Info.getBlockData();
 
 			// Read block 900 from the repository
 			BlockData block900RepositoryData = repository.getBlockRepository().fromHeight(900);
@@ -200,10 +201,10 @@ public class BlockArchiveTests extends Common {
 
 				// Read a block from the archive
 				BlockArchiveReader reader = BlockArchiveReader.getInstance();
-				Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = reader.fetchBlockAtHeight(testHeight);
-				BlockData archivedBlockData = blockInfo.getA();
-				ATStateData archivedAtStateData = blockInfo.getC().isEmpty() ? null : blockInfo.getC().get(0);
-				List<TransactionData> archivedTransactions = blockInfo.getB();
+				BlockTransformation blockInfo = reader.fetchBlockAtHeight(testHeight);
+				BlockData archivedBlockData = blockInfo.getBlockData();
+				ATStateData archivedAtStateData = blockInfo.getAtStates().isEmpty() ? null : blockInfo.getAtStates().get(0);
+				List<TransactionData> archivedTransactions = blockInfo.getTransactions();
 
 				// Read the same block from the repository
 				BlockData repositoryBlockData = repository.getBlockRepository().fromHeight(testHeight);
@@ -255,7 +256,7 @@ public class BlockArchiveTests extends Common {
 
 			// Check block 10 (unarchived)
 			BlockArchiveReader reader = BlockArchiveReader.getInstance();
-			Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = reader.fetchBlockAtHeight(10);
+			BlockTransformation blockInfo = reader.fetchBlockAtHeight(10);
 			assertNull(blockInfo);
 
 		}

src/test/java/org/qortal/test/BlockTests.java

@@ -24,6 +24,7 @@ import org.qortal.test.common.TransactionUtils;
 import org.qortal.transaction.Transaction;
 import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformation;
 import org.qortal.transform.block.BlockTransformer;
 import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.Base58;
@@ -121,10 +122,10 @@ public class BlockTests extends Common {
 
 			assertEquals(BlockTransformer.getDataLength(block), bytes.length);
 
-			Triple<BlockData, List<TransactionData>, List<ATStateData>> blockInfo = BlockTransformer.fromBytes(bytes);
+			BlockTransformation blockInfo = BlockTransformer.fromBytes(bytes);
 
 			// Compare transactions
-			List<TransactionData> deserializedTransactions = blockInfo.getB();
+			List<TransactionData> deserializedTransactions = blockInfo.getTransactions();
 			assertEquals("Transaction count differs", blockData.getTransactionCount(), deserializedTransactions.size());
 
 			for (int i = 0; i < blockData.getTransactionCount(); ++i) {

src/test/java/org/qortal/test/TransactionReferenceTests.java

@@ -0,0 +1,165 @@
+package org.qortal.test;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.data.transaction.PaymentTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.test.common.transaction.TestTransaction;
+import org.qortal.transaction.Transaction;
+
+import java.util.Random;
+
+import static org.junit.Assert.assertEquals;
+
+public class TransactionReferenceTests extends Common {
+
+    @Before
+    public void beforeTest() throws DataException {
+        Common.useDefaultSettings();
+    }
+
+    @Test
+    public void testInvalidRandomReferenceBeforeFeatureTrigger() throws DataException {
+        Random random = new Random();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+
+            byte[] randomPrivateKey = new byte[32];
+            random.nextBytes(randomPrivateKey);
+            PrivateKeyAccount recipient = new PrivateKeyAccount(repository, randomPrivateKey);
+
+            // Create payment transaction data
+            TransactionData paymentTransactionData = new PaymentTransactionData(TestTransaction.generateBase(alice), recipient.getAddress(), 100000L);
+
+            // Set random reference
+            byte[] randomReference = new byte[64];
+            random.nextBytes(randomReference);
+            paymentTransactionData.setReference(randomReference);
+
+            Transaction paymentTransaction = Transaction.fromData(repository, paymentTransactionData);
+
+            // Transaction should be invalid due to random reference
+            Transaction.ValidationResult validationResult = paymentTransaction.isValidUnconfirmed();
+            assertEquals(Transaction.ValidationResult.INVALID_REFERENCE, validationResult);
+        }
+    }
+
+    @Test
+    public void testValidRandomReferenceAfterFeatureTrigger() throws DataException {
+        Common.useSettings("test-settings-v2-disable-reference.json");
+        Random random = new Random();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+
+            byte[] randomPrivateKey = new byte[32];
+            random.nextBytes(randomPrivateKey);
+            PrivateKeyAccount recipient = new PrivateKeyAccount(repository, randomPrivateKey);
+
+            // Create payment transaction data
+            TransactionData paymentTransactionData = new PaymentTransactionData(TestTransaction.generateBase(alice), recipient.getAddress(), 100000L);
+
+            // Set random reference
+            byte[] randomReference = new byte[64];
+            random.nextBytes(randomReference);
+            paymentTransactionData.setReference(randomReference);
+
+            Transaction paymentTransaction = Transaction.fromData(repository, paymentTransactionData);
+
+            // Transaction should be valid, even with random reference, because reference checking is now disabled
+            Transaction.ValidationResult validationResult = paymentTransaction.isValidUnconfirmed();
+            assertEquals(Transaction.ValidationResult.OK, validationResult);
+            TransactionUtils.signAndImportValid(repository, paymentTransactionData, alice);
+        }
+    }
+
+    @Test
+    public void testNullReferenceAfterFeatureTrigger() throws DataException {
+        Common.useSettings("test-settings-v2-disable-reference.json");
+        Random random = new Random();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+
+            byte[] randomPrivateKey = new byte[32];
+            random.nextBytes(randomPrivateKey);
+            PrivateKeyAccount recipient = new PrivateKeyAccount(repository, randomPrivateKey);
+
+            // Create payment transaction data
+            TransactionData paymentTransactionData = new PaymentTransactionData(TestTransaction.generateBase(alice), recipient.getAddress(), 100000L);
+
+            // Set null reference
+            paymentTransactionData.setReference(null);
+
+            Transaction paymentTransaction = Transaction.fromData(repository, paymentTransactionData);
+
+            // Transaction should be invalid, as we require a non-null reference
+            Transaction.ValidationResult validationResult = paymentTransaction.isValidUnconfirmed();
+            assertEquals(Transaction.ValidationResult.INVALID_REFERENCE, validationResult);
+        }
+    }
+
+    @Test
+    public void testShortReferenceAfterFeatureTrigger() throws DataException {
+        Common.useSettings("test-settings-v2-disable-reference.json");
+        Random random = new Random();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+
+            byte[] randomPrivateKey = new byte[32];
+            random.nextBytes(randomPrivateKey);
+            PrivateKeyAccount recipient = new PrivateKeyAccount(repository, randomPrivateKey);
+
+            // Create payment transaction data
+            TransactionData paymentTransactionData = new PaymentTransactionData(TestTransaction.generateBase(alice), recipient.getAddress(), 100000L);
+
+            // Set a 1-byte reference
+            byte[] randomByte = new byte[63];
+            random.nextBytes(randomByte);
+            paymentTransactionData.setReference(randomByte);
+
+            Transaction paymentTransaction = Transaction.fromData(repository, paymentTransactionData);
+
+            // Transaction should be invalid, as reference isn't long enough
+            Transaction.ValidationResult validationResult = paymentTransaction.isValidUnconfirmed();
+            assertEquals(Transaction.ValidationResult.INVALID_REFERENCE, validationResult);
+        }
+    }
+
+    @Test
+    public void testLongReferenceAfterFeatureTrigger() throws DataException {
+        Common.useSettings("test-settings-v2-disable-reference.json");
+        Random random = new Random();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+
+            byte[] randomPrivateKey = new byte[32];
+            random.nextBytes(randomPrivateKey);
+            PrivateKeyAccount recipient = new PrivateKeyAccount(repository, randomPrivateKey);
+
+            // Create payment transaction data
+            TransactionData paymentTransactionData = new PaymentTransactionData(TestTransaction.generateBase(alice), recipient.getAddress(), 100000L);
+
+            // Set a 1-byte reference
+            byte[] randomByte = new byte[65];
+            random.nextBytes(randomByte);
+            paymentTransactionData.setReference(randomByte);
+
+            Transaction paymentTransaction = Transaction.fromData(repository, paymentTransactionData);
+
+            // Transaction should be invalid, as reference is too long
+            Transaction.ValidationResult validationResult = paymentTransaction.isValidUnconfirmed();
+            assertEquals(Transaction.ValidationResult.INVALID_REFERENCE, validationResult);
+        }
+    }
+
+}

src/test/java/org/qortal/test/common/Common.java

@@ -61,6 +61,7 @@ public class Common {
 
 
 	public static final String testSettingsFilename = "test-settings-v2.json";
+	public static boolean shouldRetainRepositoryAfterTest = false;
 
 	static {
 		// Load/check settings, which potentially sets up blockchain config, etc.
@@ -126,6 +127,7 @@ public class Common {
 
 	public static void useSettings(String settingsFilename) throws DataException {
 		Common.useSettingsAndDb(settingsFilename, true);
+		setShouldRetainRepositoryAfterTest(false);
 	}
 
 	public static void useDefaultSettings() throws DataException {
@@ -207,7 +209,16 @@ public class Common {
 		RepositoryManager.setRepositoryFactory(repositoryFactory);
 	}
 
+	public static void setShouldRetainRepositoryAfterTest(boolean shouldRetain) {
+		shouldRetainRepositoryAfterTest = shouldRetain;
+	}
+
 	public static void deleteTestRepository() throws DataException {
+		if (shouldRetainRepositoryAfterTest) {
+			// Don't delete if we've requested to keep the db intact
+			return;
+		}
+
 		// Delete repository directory if exists
 		Path repositoryPath = Paths.get(Settings.getInstance().getRepositoryPath());
 		try {

src/test/java/org/qortal/test/crosschain/bitcoinv3/BitcoinACCTv3Tests.java

@@ -0,0 +1,769 @@
+package org.qortal.test.crosschain.bitcoinv3;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.Account;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.block.Block;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crosschain.BitcoinACCTv3;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.utils.Amounts;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+
+import static org.junit.Assert.*;
+
+public class BitcoinACCTv3Tests extends Common {
+
+	public static final byte[] secretA = "This string is exactly 32 bytes!".getBytes();
+	public static final byte[] hashOfSecretA = Crypto.hash160(secretA); // daf59884b4d1aec8c1b17102530909ee43c0151a
+	public static final byte[] bitcoinPublicKeyHash = HashCode.fromString("bb00bb11bb22bb33bb44bb55bb66bb77bb88bb99").asBytes();
+	public static final int tradeTimeout = 20; // blocks
+	public static final long redeemAmount = 80_40200000L;
+	public static final long fundingAmount = 123_45600000L;
+	public static final long bitcoinAmount = 864200L; // 0.00864200 BTC
+
+	private static final Random RANDOM = new Random();
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testCompile() {
+		PrivateKeyAccount tradeAccount = createTradeAccount(null);
+
+		byte[] creationBytes = BitcoinACCTv3.buildQortalAT(tradeAccount.getAddress(), bitcoinPublicKeyHash, redeemAmount, bitcoinAmount, tradeTimeout);
+		assertNotNull(creationBytes);
+
+		System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+	}
+
+	@Test
+	public void testDeploy() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			long expectedBalance = deployersInitialBalance - fundingAmount - deployAtTransaction.getTransactionData().getFee();
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = fundingAmount;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			expectedBalance = deployersInitialBalance;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = 0;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancel() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Send creator's address to AT, instead of typical partner's address
+			byte[] messageData = BitcoinACCTv3.getInstance().buildCancelMessage(deployer.getAddress());
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+
+			// Check balances
+			long expectedMinimumBalance = deployersPostDeploymentBalance;
+			long expectedMaximumBalance = deployersInitialBalance - deployAtFee - messageFee;
+
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+			assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance - messageFee;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancelInvalidLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Instead of sending creator's address to AT, send too-short/invalid message
+			byte[] messageData = new byte[7];
+			RANDOM.nextBytes(messageData);
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			// As message is too short, it will be padded to 32bytes but cancel code doesn't care about message content, so should be ok
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testTradingInfoProcessing() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should be in TRADE mode
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check hashOfSecretA was extracted correctly
+			assertTrue(Arrays.equals(hashOfSecretA, tradeData.hashOfSecretA));
+
+			// Check trade partner Qortal address was extracted correctly
+			assertEquals(partner.getAddress(), tradeData.qortalPartnerAddress);
+
+			// Check trade partner's Bitcoin PKH was extracted correctly
+			assertTrue(Arrays.equals(bitcoinPublicKeyHash, tradeData.partnerForeignPKH));
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	// TEST SENDING TRADING INFO BUT NOT FROM AT CREATOR (SHOULD BE IGNORED)
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectTradeSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT BUT NOT FROM AT CREATOR
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			BlockUtils.mintBlock(repository);
+
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-initial-payout balance incorrect", expectedBalance, actualBalance);
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+			// AT should still be in OFFER mode
+			assertEquals(AcctMode.OFFERING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testAutomaticTradeRefund() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			// Check refund
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REFUNDED mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REFUNDED, tradeData.mode);
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account
+			messageData = BitcoinACCTv3.buildRedeemMessage(secretA,  partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REDEEMED mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REDEEMED, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() + redeemAmount;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Orphan redeem
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Check AT state
+			ATStateData postOrphanAtStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertTrue("AT states mismatch", Arrays.equals(preRedeemAtStateData.getStateData(), postOrphanAtStateData.getStateData()));
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretIncorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, but from wrong account
+			messageData = BitcoinACCTv3.buildRedeemMessage(secretA, partner.getAddress());
+			messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send incorrect secret to AT, from correct account
+			byte[] wrongSecret = new byte[32];
+			RANDOM.nextBytes(wrongSecret);
+			messageData = BitcoinACCTv3.buildRedeemMessage(wrongSecret, partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSenderInvalidMessageLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = BitcoinACCTv3.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = BitcoinACCTv3.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account, but missing receive address, hence incorrect length
+			messageData = Bytes.concat(secretA);
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should be in TRADING mode
+			CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testDescribeDeployed() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			List<ATData> executableAts = repository.getATRepository().getAllExecutableATs();
+
+			for (ATData atData : executableAts) {
+				String atAddress = atData.getATAddress();
+				byte[] codeBytes = atData.getCodeBytes();
+				byte[] codeHash = Crypto.digest(codeBytes);
+
+				System.out.println(String.format("%s: code length: %d byte%s, code hash: %s",
+						atAddress,
+						codeBytes.length,
+						(codeBytes.length != 1 ? "s": ""),
+						HashCode.fromBytes(codeHash)));
+
+				// Not one of ours?
+				if (!Arrays.equals(codeHash, BitcoinACCTv3.CODE_BYTES_HASH))
+					continue;
+
+				describeAt(repository, atAddress);
+			}
+		}
+	}
+
+	private int calcTestLockTimeA(long messageTimestamp) {
+		return (int) (messageTimestamp / 1000L + tradeTimeout * 60);
+	}
+
+	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, String tradeAddress) throws DataException {
+		byte[] creationBytes = BitcoinACCTv3.buildQortalAT(tradeAddress, bitcoinPublicKeyHash, redeemAmount, bitcoinAmount, tradeTimeout);
+
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = deployer.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", deployer.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		String name = "QORT-BTC cross-chain trade";
+		String description = String.format("Qortal-Bitcoin cross-chain trade");
+		String atType = "ACCT";
+		String tags = "QORT-BTC ACCT";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, deployer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, deployAtTransactionData, deployer);
+
+		return deployAtTransaction;
+	}
+
+	private MessageTransaction sendMessage(Repository repository, PrivateKeyAccount sender, byte[] data, String recipient) throws DataException {
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = sender.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", sender.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		int version = 4;
+		int nonce = 0;
+		long amount = 0;
+		Long assetId = null; // because amount is zero
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, sender.getPublicKey(), fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, recipient, amount, assetId, data, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		fee = messageTransaction.calcRecommendedFee();
+		messageTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, messageTransactionData, sender);
+
+		return messageTransaction;
+	}
+
+	private void checkTradeRefund(Repository repository, Account deployer, long deployersInitialBalance, long deployAtFee) throws DataException {
+		long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+		int refundTimeout = tradeTimeout / 2 + 1; // close enough
+
+		// AT should automatically refund deployer after 'refundTimeout' blocks
+		for (int blockCount = 0; blockCount <= refundTimeout; ++blockCount)
+			BlockUtils.mintBlock(repository);
+
+		// We don't bother to exactly calculate QORT spent running AT for several blocks, but we do know the expected range
+		long expectedMinimumBalance = deployersPostDeploymentBalance;
+		long expectedMaximumBalance = deployersInitialBalance - deployAtFee;
+
+		long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+		assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+		assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+	}
+
+	private void describeAt(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		CrossChainTradeData tradeData = BitcoinACCTv3.getInstance().populateTradeData(repository, atData);
+
+		Function<Long, String> epochMilliFormatter = (timestamp) -> LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneOffset.UTC).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM));
+		int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
+
+		System.out.print(String.format("%s:\n"
+				+ "\tmode: %s\n"
+				+ "\tcreator: %s,\n"
+				+ "\tcreation timestamp: %s,\n"
+				+ "\tcurrent balance: %s QORT,\n"
+				+ "\tis finished: %b,\n"
+				+ "\tredeem payout: %s QORT,\n"
+				+ "\texpected Bitcoin: %s BTC,\n"
+				+ "\tcurrent block height: %d,\n",
+				tradeData.qortalAtAddress,
+				tradeData.mode,
+				tradeData.qortalCreator,
+				epochMilliFormatter.apply(tradeData.creationTimestamp),
+				Amounts.prettyAmount(tradeData.qortBalance),
+				atData.getIsFinished(),
+				Amounts.prettyAmount(tradeData.qortAmount),
+				Amounts.prettyAmount(tradeData.expectedForeignAmount),
+				currentBlockHeight));
+
+		if (tradeData.mode != AcctMode.OFFERING && tradeData.mode != AcctMode.CANCELLED) {
+			System.out.println(String.format("\trefund timeout: %d minutes,\n"
+					+ "\trefund height: block %d,\n"
+					+ "\tHASH160 of secret-A: %s,\n"
+					+ "\tBitcoin P2SH-A nLockTime: %d (%s),\n"
+					+ "\ttrade partner: %s\n"
+					+ "\tpartner's receiving address: %s",
+					tradeData.refundTimeout,
+					tradeData.tradeRefundHeight,
+					HashCode.fromBytes(tradeData.hashOfSecretA).toString().substring(0, 40),
+					tradeData.lockTimeA, epochMilliFormatter.apply(tradeData.lockTimeA * 1000L),
+					tradeData.qortalPartnerAddress,
+					tradeData.qortalPartnerReceivingAddress));
+		}
+	}
+
+	private PrivateKeyAccount createTradeAccount(Repository repository) {
+		// We actually use a known test account with funds to avoid PoW compute
+		return Common.getTestAccount(repository, "alice");
+	}
+
+}

src/test/java/org/qortal/test/naming/IntegrityTests.java

@@ -509,6 +509,7 @@ public class IntegrityTests extends Common {
     @Ignore("Checks 'live' repository")
     @Test
     public void testRepository() throws DataException {
+        Common.setShouldRetainRepositoryAfterTest(true);
         Settings.fileInstance("settings.json"); // use 'live' settings
 
         String repositoryUrlTemplate = "jdbc:hsqldb:file:%s" + File.separator + "blockchain;create=false;hsqldb.full_log_replay=true";

src/test/resources/test-chain-v2-disable-reference.json

@@ -0,0 +1,84 @@
+{
+	"isTestChain": true,
+	"blockTimestampMargin": 500,
+	"transactionExpiryPeriod": 86400000,
+	"maxBlockSize": 2097152,
+	"maxBytesPerUnitFee": 1024,
+	"unitFee": "0.1",
+	"nameRegistrationUnitFees": [
+		{ "timestamp": 1645372800000, "fee": "5" }
+	],
+	"requireGroupForApproval": false,
+	"minAccountLevelToRewardShare": 5,
+	"maxRewardSharesPerMintingAccount": 20,
+	"founderEffectiveMintingLevel": 10,
+	"onlineAccountSignaturesMinLifetime": 3600000,
+	"onlineAccountSignaturesMaxLifetime": 86400000,
+	"rewardsByHeight": [
+		{ "height": 1, "reward": 100 },
+		{ "height": 11, "reward": 10 },
+		{ "height": 21, "reward": 1 }
+	],
+	"sharesByLevel": [
+		{ "levels": [ 1, 2 ], "share": 0.05 },
+		{ "levels": [ 3, 4 ], "share": 0.10 },
+		{ "levels": [ 5, 6 ], "share": 0.15 },
+		{ "levels": [ 7, 8 ], "share": 0.20 },
+		{ "levels": [ 9, 10 ], "share": 0.25 }
+	],
+	"qoraHoldersShare": 0.20,
+	"qoraPerQortReward": 250,
+	"blocksNeededByLevel": [ 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 ],
+	"blockTimingsByHeight": [
+		{ "height": 1, "target": 60000, "deviation": 30000, "power": 0.2 }
+	],
+	"ciyamAtSettings": {
+		"feePerStep": "0.0001",
+		"maxStepsPerRound": 500,
+		"stepsPerFunctionCall": 10,
+		"minutesPerBlock": 1
+	},
+	"featureTriggers": {
+		"messageHeight": 0,
+		"atHeight": 0,
+		"assetsTimestamp": 0,
+		"votingTimestamp": 0,
+		"arbitraryTimestamp": 0,
+		"powfixTimestamp": 0,
+		"qortalTimestamp": 0,
+		"newAssetPricingTimestamp": 0,
+		"groupApprovalTimestamp": 0,
+		"atFindNextTransactionFix": 0,
+		"newBlockSigHeight": 999999,
+		"shareBinFix": 999999,
+		"calcChainWeightTimestamp": 0,
+		"transactionV5Timestamp": 0,
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 0
+	},
+	"genesisInfo": {
+		"version": 4,
+		"timestamp": 0,
+		"transactions": [
+			{ "type": "ISSUE_ASSET", "assetName": "QORT", "description": "QORT native coin", "data": "", "quantity": 0, "isDivisible": true, "fee": 0 },
+			{ "type": "ISSUE_ASSET", "assetName": "Legacy-QORA", "description": "Representative legacy QORA", "quantity": 0, "isDivisible": true, "data": "{}", "isUnspendable": true },
+			{ "type": "ISSUE_ASSET", "assetName": "QORT-from-QORA", "description": "QORT gained from holding legacy QORA", "quantity": 0, "isDivisible": true, "data": "{}", "isUnspendable": true },
+
+			{ "type": "GENESIS", "recipient": "QgV4s3xnzLhVBEJxcYui4u4q11yhUHsd9v", "amount": "1000000000" },
+			{ "type": "GENESIS", "recipient": "QixPbJUwsaHsVEofJdozU9zgVqkK6aYhrK", "amount": "1000000" },
+			{ "type": "GENESIS", "recipient": "QaUpHNhT3Ygx6avRiKobuLdusppR5biXjL", "amount": "1000000" },
+			{ "type": "GENESIS", "recipient": "Qci5m9k4rcwe4ruKrZZQKka4FzUUMut3er", "amount": "1000000" },
+
+			{ "type": "CREATE_GROUP", "creatorPublicKey": "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP", "groupName": "dev-group", "description": "developer group", "isOpen": false, "approvalThreshold": "PCT100", "minimumBlockDelay": 0, "maximumBlockDelay": 1440 },
+
+			{ "type": "ISSUE_ASSET", "issuerPublicKey": "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP", "assetName": "TEST", "description": "test asset", "data": "", "quantity": "1000000", "isDivisible": true, "fee": 0 },
+			{ "type": "ISSUE_ASSET", "issuerPublicKey": "C6wuddsBV3HzRrXUtezE7P5MoRXp5m3mEDokRDGZB6ry", "assetName": "OTHER", "description": "other test asset", "data": "", "quantity": "1000000", "isDivisible": true, "fee": 0 },
+			{ "type": "ISSUE_ASSET", "issuerPublicKey": "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP", "assetName": "GOLD", "description": "gold test asset", "data": "", "quantity": "1000000", "isDivisible": true, "fee": 0 },
+
+			{ "type": "ACCOUNT_FLAGS", "target": "QgV4s3xnzLhVBEJxcYui4u4q11yhUHsd9v", "andMask": -1, "orMask": 1, "xorMask": 0 },
+			{ "type": "REWARD_SHARE", "minterPublicKey": "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP", "recipient": "QgV4s3xnzLhVBEJxcYui4u4q11yhUHsd9v", "rewardSharePublicKey": "7PpfnvLSG7y4HPh8hE7KoqAjLCkv7Ui6xw4mKAkbZtox", "sharePercent": "100" },
+
+			{ "type": "ACCOUNT_LEVEL", "target": "Qci5m9k4rcwe4ruKrZZQKka4FzUUMut3er", "level": 5 }
+		]
+	}
+}

src/test/resources/test-chain-v2-founder-rewards.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-leftover-reward.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-minting.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-qora-holder-extremes.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-qora-holder.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-reward-levels.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 6,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2-reward-scaling.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-chain-v2.json

@@ -53,7 +53,8 @@
 		"shareBinFix": 999999,
 		"calcChainWeightTimestamp": 0,
 		"transactionV5Timestamp": 0,
-		"transactionV6Timestamp": 0
+		"transactionV6Timestamp": 0,
+		"disableReferenceTimestamp": 9999999999999
 	},
 	"genesisInfo": {
 		"version": 4,

src/test/resources/test-settings-v2-disable-reference.json

@@ -0,0 +1,11 @@
+{
+  "repositoryPath": "testdb",
+  "restrictedApi": false,
+  "blockchainConfig": "src/test/resources/test-chain-v2-disable-reference.json",
+  "exportPath": "qortal-backup-test",
+  "bootstrap": false,
+  "wipeUnconfirmedOnStart": false,
+  "testNtpOffset": 0,
+  "minPeers": 0,
+  "pruneBlockLimit": 100
+}