Merge pull request #254 from jschulthess/reticulum

Reticulum branch updates

.vscode/settings.json

@@ -1,3 +0,0 @@
-{
-    "java.compile.nullAnalysis.mode": "automatic"
-}

log4j2.properties

@@ -6,6 +6,34 @@ rootLogger.level = info
 rootLogger.appenderRef.console.ref = stdout
 rootLogger.appenderRef.rolling.ref = FILE
 
+### additional debug options (in case of problems eg. 202411
+
+#to see more QDN details - add the stuff below
+#logger.arbitrary.name = org.qortal.arbitrary
+#logger.arbitrary.level = trace
+
+#to see more QDN networking details - add stuff below
+#logger.arbitrarycontroller.name = org.qortal.controller.arbitrary
+#logger.arbitrarycontroller.level = debug
+
+# Support optional, Network Task debugging
+#logger.networkTask.name = org.qortal.network.task
+#logger.networkTask.level = debug
+
+# Support optional, Network Task tracing
+#logger.networkTask.name = org.qortal.network.task
+#logger.networkTask.level = trace
+
+# Support optional, Block debugging
+#logger.block.name = org.qortal.block
+#logger.block.level = debug
+
+# Support optional, Block tracing
+#logger.block.name = org.qortal.block
+#logger.block.level = trace
+
+### end additional debug options
+
 # Suppress extraneous bitcoinj library output
 logger.bitcoinj.name = org.bitcoinj
 logger.bitcoinj.level = error
@@ -18,6 +46,10 @@ logger.hsqldb.level = warn
 logger.hsqldbRepository.name = org.qortal.repository.hsqldb
 logger.hsqldbRepository.level = debug
 
+## Support optional, controller repository debugging
+#logger.controllerRepository.name = org.qortal.controller.repository
+#logger.controllerRepository.level = debug
+
 # Suppress extraneous Jersey warning
 logger.jerseyInject.name = org.glassfish.jersey.internal.inject.Providers
 logger.jerseyInject.level = off

pom.xml

@@ -52,12 +52,17 @@
 		<maven-surefire-plugin.version>3.5.2</maven-surefire-plugin.version>
 		<protobuf.version>3.25.3</protobuf.version>
 		<replacer.version>1.5.3</replacer.version>
+		<reticulum.version>8623ce3</reticulum.version>
 		<simplemagic.version>1.17</simplemagic.version>
-		<slf4j.version>1.7.36</slf4j.version>
 		<swagger-api.version>2.0.10</swagger-api.version>
 		<swagger-ui.version>5.18.2</swagger-ui.version>
 		<upnp.version>1.2</upnp.version>
 		<xz.version>1.10</xz.version>
+   	<lombok.version>1.18.30</lombok.version>
+   	<jackson.version>2.16.1</jackson.version>
+		<slf4j.version>2.0.12</slf4j.version>
+    <nitrite.version>4.3.0</nitrite.version>
+    <junit.version>5.9.2</junit.version>
 	</properties>
 	<build>
 		<sourceDirectory>src/main/java</sourceDirectory>
@@ -426,13 +431,41 @@
 			<id>project.local</id>
 			<name>project</name>
 			<url>file:${project.basedir}/lib</url>
+      <snapshots>
+        <enabled>true</enabled>
+        <updatePolicy>always</updatePolicy>
+      </snapshots>
 		</repository>
 		<!-- jitpack for build-on-demand of altcoinj -->
 		<repository>
 			<id>jitpack.io</id>
 			<url>https://jitpack.io</url>
+      <snapshots>
+        <enabled>true</enabled>
+        <updatePolicy>always</updatePolicy>
+      </snapshots>
 		</repository>
 	</repositories>
+	<!--
+    <dependencyManagement>
+      <dependencies>
+        <dependency>
+          <groupId>org.dizitart</groupId>
+          <artifactId>nitrite-bom</artifactId>
+          <version>${nitrite.version}</version>
+          <scope>import</scope>
+          <type>pom</type>
+        </dependency>
+        <dependency>
+          <groupId>org.apache.logging.log4j</groupId>
+          <artifactId>log4j-bom</artifactId>
+          <version>${log4j.version}</version>
+          <scope>import</scope>
+          <type>pom</type>
+        </dependency>
+      </dependencies>
+  	</dependencyManagement>
+    -->
 	<dependencies>
 		<!-- https://mvnrepository.com/artifact/org.codehaus.mojo/build-helper-maven-plugin -->
 		<dependency>
@@ -480,6 +513,13 @@
 			<artifactId>altcoinj</artifactId>
 			<version>${altcoinj.version}</version>
 		</dependency>
+		<!-- Build Reticulum from Source -->
+		<dependency>
+			<!--<groupId>com.github.sergst83</groupId>-->
+			<groupId>com.github.jschulthess</groupId>
+			<artifactId>reticulum-network-stack</artifactId>
+			<version>${reticulum.version}</version>
+		</dependency>
 		<!-- Utilities -->
 		<dependency>
 			<groupId>com.googlecode.json-simple</groupId>
@@ -558,35 +598,33 @@
 			<artifactId>guava</artifactId>
 			<version>${guava.version}</version>
 		</dependency>
-		<!-- Logging: log4j2 -->
-		<dependency>
-			<groupId>org.apache.logging.log4j</groupId>
-			<artifactId>log4j-core</artifactId>
-			<version>${log4j.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.logging.log4j</groupId>
-			<artifactId>log4j-api</artifactId>
-			<version>${log4j.version}</version>
-		</dependency>
-		<!-- redirect slf4j to log4j2 -->
-		<dependency>
-			<groupId>org.apache.logging.log4j</groupId>
-			<artifactId>log4j-slf4j-impl</artifactId>
-			<version>${log4j.version}</version>
-		</dependency>
-		<!-- redirect java.utils.logging to log4j2 -->
-		<dependency>
-			<groupId>org.apache.logging.log4j</groupId>
-			<artifactId>log4j-jul</artifactId>
-			<version>${log4j.version}</version>
-		</dependency>
-		<!-- Logging: slf4j used by Jetty/Jersey -->
+    <!-- logging: slf4j -->
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-api</artifactId>
 			<version>${slf4j.version}</version>
 		</dependency>
+    <dependency>
+       <groupId>org.apache.logging.log4j</groupId>
+       <artifactId>log4j-slf4j2-impl</artifactId>
+       <version>${log4j.version}</version>
+    </dependency>
+		<!-- Logging: log4j2 -->
+    <dependency>
+       <groupId>org.apache.logging.log4j</groupId>
+       <artifactId>log4j-core</artifactId>
+       <version>${log4j.version}</version>
+    </dependency>
+    <dependency>
+    <groupId>org.apache.logging.log4j</groupId>
+       <artifactId>log4j-api</artifactId>
+       <version>${log4j.version}</version>
+    </dependency>
+    <dependency>
+       <groupId>org.apache.logging.log4j</groupId>
+       <artifactId>log4j-jul</artifactId>
+       <version>${log4j.version}</version>
+     </dependency> 
 		<!-- Servlet related -->
 		<dependency>
 			<groupId>javax.servlet</groupId>
@@ -728,6 +766,11 @@
 			<groupId>org.bouncycastle</groupId>
 			<artifactId>bctls-jdk15on</artifactId>
 			<version>${bouncycastle.version}</version>
+		</dependency><!-- https://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk15to18 -->
+		<dependency>
+		    <groupId>org.bouncycastle</groupId>
+		    <artifactId>bcprov-jdk15to18</artifactId>
+		    <version>${bouncycastle.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>org.jsoup</groupId>
@@ -770,5 +813,123 @@
 			<artifactId>jaxb-runtime</artifactId>
 			<version>${jaxb-runtime.version}</version>
 		</dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>${jackson.version}</version>
+    </dependency>
+    <!-- https://mvnrepository.com/artifact/commons-codec/commons-codec -->
+    <dependency>
+      <groupId>commons-codec</groupId>
+      <artifactId>commons-codec</artifactId>
+      <version>1.16.1</version>
+    </dependency>
+    <!-- already declared earlier
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+      <version>3.14.0</version>
+    </dependency>
+    -->
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-collections4</artifactId>
+      <version>4.4</version>
+    </dependency>
+    <!-- already declared earlier
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-compress</artifactId>
+      <version>1.26.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <version>${slf4j.version}</version>
+    </dependency>
+    -->
+    <!-- note: covered ? -->
+    <dependency>
+      <groupId>com.fasterxml.jackson.dataformat</groupId>
+      <artifactId>jackson-dataformat-yaml</artifactId>
+      <version>${jackson.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.yaml</groupId>
+      <artifactId>snakeyaml</artifactId>
+      <version>2.2</version>
+    </dependency>
+    <dependency>
+      <groupId>org.msgpack</groupId>
+      <artifactId>jackson-dataformat-msgpack</artifactId>
+      <version>0.9.8</version>
+    </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>${lombok.version}</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.bouncycastle</groupId>
+      <artifactId>bcpkix-jdk15on</artifactId>
+      <version>1.70</version>
+    </dependency>
+    <dependency>
+      <groupId>com.macasaet.fernet</groupId>
+      <artifactId>fernet-java8</artifactId>
+      <version>1.5.0</version>
+    </dependency>
+    <dependency>
+      <groupId>com.igormaznitsa</groupId>
+      <artifactId>jbbp</artifactId>
+      <version>2.0.6</version>
+    </dependency>
+    <dependency>
+      <groupId>io.netty</groupId>
+      <artifactId>netty-all</artifactId>
+      <!--<version>4.1.106.Final</version>-->
+      <version>5.0.0.Alpha2</version>
+    </dependency>
+    <dependency>
+      <groupId>com.github.seancfoley</groupId>
+      <artifactId>ipaddress</artifactId>
+      <version>5.4.2</version>
+    </dependency>
+    <!-- Nitrite Modules -->
+    <dependency>
+        <groupId>org.dizitart</groupId>
+        <artifactId>nitrite</artifactId>
+        <version>${nitrite.version}</version>
+    </dependency>
+    <dependency>
+        <groupId>org.dizitart</groupId>
+        <artifactId>nitrite-mvstore-adapter</artifactId>
+        <version>${nitrite.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.h2database</groupId>
+      <artifactId>h2</artifactId>
+      <version>2.3.230</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.h2database</groupId>
+      <artifactId>h2-mvstore</artifactId>
+      <version>2.3.230</version>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>${junit.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+
 	</dependencies>
 </project>

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

@@ -18,6 +18,7 @@ import org.qortal.controller.hsqldb.HSQLDBDataCacheManager;
 import org.qortal.controller.repository.NamesDatabaseIntegrityCheck;
 import org.qortal.controller.repository.PruneManager;
 import org.qortal.controller.tradebot.TradeBot;
+import org.qortal.controller.tradebot.RNSTradeBot;
 import org.qortal.data.account.AccountBalanceData;
 import org.qortal.data.account.AccountData;
 import org.qortal.data.block.BlockData;
@@ -33,6 +34,8 @@ import org.qortal.globalization.Translator;
 import org.qortal.gui.Gui;
 import org.qortal.gui.SysTray;
 import org.qortal.network.Network;
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
 import org.qortal.network.Peer;
 import org.qortal.network.PeerAddress;
 import org.qortal.network.message.*;
@@ -123,6 +126,7 @@ public class Controller extends Thread {
 	private long repositoryCheckpointTimestamp = startTime; // ms
 	private long prunePeersTimestamp = startTime; // ms
 	private long ntpCheckTimestamp = startTime; // ms
+	private long pruneRNSPeersTimestamp = startTime; // ms
 	private long deleteExpiredTimestamp = startTime + DELETE_EXPIRED_INTERVAL; // ms
 
 	/** Whether we can mint new blocks, as reported by BlockMinter. */
@@ -519,6 +523,15 @@ public class Controller extends Thread {
 			return; // Not System.exit() so that GUI can display error
 		}
 
+		LOGGER.info("Starting Reticulum");
+		try {
+			RNSNetwork rns = RNSNetwork.getInstance();
+			rns.start();
+			LOGGER.debug("Reticulum instance: {}", rns.toString());
+		} catch (IOException | DataException e) {
+			LOGGER.error("Unable to start Reticulum", e);
+		}
+
 		Runtime.getRuntime().addShutdownHook(new Thread() {
 			@Override
 			public void run() {
@@ -530,6 +543,9 @@ public class Controller extends Thread {
 		LOGGER.info("Starting synchronizer");
 		Synchronizer.getInstance().start();
 
+		LOGGER.info("Starting synchronizer over Reticulum");
+		RNSSynchronizer.getInstance().start();
+
 		LOGGER.info("Starting block minter");
 		blockMinter = new BlockMinter();
 		blockMinter.start();
@@ -727,6 +743,73 @@ public class Controller extends Thread {
 				}
 			}
 		}, 3*60*1000, 3*60*1000);
+		//Timer syncFromGenesisRNS = new Timer();
+		//syncFromGenesisRNS.schedule(new TimerTask() {
+		//	@Override
+		//	public void run() {
+		//		LOGGER.debug("Start sync from genesis check (RNS).");
+		//		boolean canBootstrap = Settings.getInstance().getBootstrap();
+		//		boolean needsArchiveRebuildRNS = false;
+		//		int checkHeightRNS = 0;
+		//
+		//		try (final Repository repository = RepositoryManager.getRepository()){
+		//			needsArchiveRebuildRNS = (repository.getBlockArchiveRepository().fromHeight(2) == null);
+		//			checkHeightRNS = repository.getBlockRepository().getBlockchainHeight();
+		//		} catch (DataException e) {
+		//			throw new RuntimeException(e);
+		//		}
+		//
+		//		if (canBootstrap || !needsArchiveRebuildRNS || checkHeightRNS > 3) {
+		//			LOGGER.debug("Bootstrapping is enabled or we have more than 2 blocks, cancel sync from genesis check.");
+		//			syncFromGenesisRNS.cancel();
+		//			return;
+		//		}
+		//
+		//		if (needsArchiveRebuildRNS && !canBootstrap) {
+		//			LOGGER.info("Start syncing from genesis (RNS)!");
+		//			List<RNSPeer> seeds = new ArrayList<>(RNSNetwork.getInstance().getActiveImmutableLinkedPeers());
+		//
+		//			// Check if have a qualified peer to sync
+		//			if (seeds.isEmpty()) {
+		//				LOGGER.info("No connected RNSPeer(s), will try again later.");
+		//				return;
+		//			}
+		//
+		//			int index = new SecureRandom().nextInt(seeds.size());
+		//			RNSPeer syncPeer = seeds.get(index);
+		//			var syncPeerLinkAsString = syncPeer.getPeerLink().toString();
+		//			//String syncNode = String.valueOf(seeds.get(index));
+		//			//PeerAddress peerAddress = PeerAddress.fromString(syncNode);
+		//			//InetSocketAddress resolvedAddress = null;
+		//			//
+		//			//try {
+		//			//	resolvedAddress = peerAddress.toSocketAddress();
+		//			//} catch (UnknownHostException e) {
+		//			//	throw new RuntimeException(e);
+		//			//}
+		//			//
+		//			//InetSocketAddress finalResolvedAddress = resolvedAddress;
+		//			//Peer targetPeer = seeds.stream().filter(peer -> peer.getResolvedAddress().equals(finalResolvedAddress)).findFirst().orElse(null);
+		//			//RNSPeer targetPeerRNS = seeds.stream().findFirst().orElse(null);
+		//			RNSPeer targetPeerRNS = seeds.stream().filter(peer -> peer.getPeerLink().toString().equals(syncPeerLinkAsString)).findFirst().orElse(null);
+		//			RNSSynchronizer.SynchronizationResult syncResultRNS;
+		//
+		//			try {
+		//				do {
+		//					try {
+		//						syncResultRNS = RNSSynchronizer.getInstance().actuallySynchronize(targetPeerRNS, true);
+		//					} catch (InterruptedException e) {
+		//						throw new RuntimeException(e);
+		//					}
+		//				}
+		//				while (syncResultRNS == RNSSynchronizer.SynchronizationResult.OK);
+		//			} finally {
+		//				// We are syncing now, so can cancel the check
+		//				syncFromGenesisRNS.cancel();
+		//			}
+		//		}
+		//	}
+		//}, 3*60*1000, 3*60*1000);
 	}
 
 	/** Called by AdvancedInstaller's launch EXE in single-instance mode, when an instance is already running. */
@@ -744,6 +827,8 @@ public class Controller extends Thread {
 		final long repositoryCheckpointInterval = Settings.getInstance().getRepositoryCheckpointInterval();
 		long repositoryMaintenanceInterval = getRandomRepositoryMaintenanceInterval();
 		final long prunePeersInterval = 5 * 60 * 1000L; // Every 5 minutes
+		//final long pruneRNSPeersInterval = 5 * 60 * 1000L; // Every 5 minutes
+		final long pruneRNSPeersInterval = 1 * 60 * 1000L; // Every 1 minute (during development)
 
 		// Start executor service for trimming or pruning
 		PruneManager.getInstance().start();
@@ -852,6 +937,18 @@ public class Controller extends Thread {
 					}
 				}
 
+				// Q: Do we need global pruning?
+				if (now >= pruneRNSPeersTimestamp + pruneRNSPeersInterval) {
+					pruneRNSPeersTimestamp = now + pruneRNSPeersInterval;
+
+					try {
+						LOGGER.debug("Pruning Reticulum peers...");
+						RNSNetwork.getInstance().prunePeers();
+					} catch (DataException e) {
+						LOGGER.warn(String.format("Repository issue when trying to prune Reticulum peers: %s", e.getMessage()));
+					}
+				}
+
 				// Delete expired transactions
 				if (now >= deleteExpiredTimestamp) {
 					deleteExpiredTimestamp = now + DELETE_EXPIRED_INTERVAL;
@@ -918,23 +1015,47 @@ public class Controller extends Thread {
 		return peerChainTipData == null || peerChainTipData.getTimestamp() == null || peerChainTipData.getTimestamp() < minLatestBlockTimestamp;
 	};
 
+	public static final Predicate<RNSPeer> hasNoRecentBlock2 = peer -> {
+		final Long minLatestBlockTimestamp = getMinimumLatestBlockTimestamp();
+		final BlockSummaryData peerChainTipData = peer.getChainTipData();
+		return peerChainTipData == null || peerChainTipData.getTimestamp() == null || peerChainTipData.getTimestamp() < minLatestBlockTimestamp;
+	};
+
 	public static final Predicate<Peer> hasNoOrSameBlock = peer -> {
 		final BlockData latestBlockData = getInstance().getChainTip();
 		final BlockSummaryData peerChainTipData = peer.getChainTipData();
 		return peerChainTipData == null || peerChainTipData.getSignature() == null || Arrays.equals(latestBlockData.getSignature(), peerChainTipData.getSignature());
 	};
 
+	public static final Predicate<RNSPeer> hasNoOrSameBlock2 = peer -> {
+		final BlockData latestBlockData = getInstance().getChainTip();
+		final BlockSummaryData peerChainTipData = peer.getChainTipData();
+		return peerChainTipData == null || peerChainTipData.getSignature() == null || Arrays.equals(latestBlockData.getSignature(), peerChainTipData.getSignature());
+	};
+
 	public static final Predicate<Peer> hasOnlyGenesisBlock = peer -> {
 		final BlockSummaryData peerChainTipData = peer.getChainTipData();
 		return peerChainTipData == null || peerChainTipData.getHeight() == 1;
 	};
 
+	public static final Predicate<RNSPeer> hasOnlyGenesisBlock2 = peer -> {
+		final BlockSummaryData peerChainTipData = peer.getChainTipData();
+		return peerChainTipData == null || peerChainTipData.getHeight() == 1;
+	};
+
+
 	public static final Predicate<Peer> hasInferiorChainTip = peer -> {
 		final BlockSummaryData peerChainTipData = peer.getChainTipData();
 		final List<ByteArray> inferiorChainTips = Synchronizer.getInstance().inferiorChainSignatures;
 		return peerChainTipData == null || peerChainTipData.getSignature() == null || inferiorChainTips.contains(ByteArray.wrap(peerChainTipData.getSignature()));
 	};
 
+	public static final Predicate<RNSPeer> hasInferiorChainTip2 = peer -> {
+		final BlockSummaryData peerChainTipData = peer.getChainTipData();
+		final List<ByteArray> inferiorChainTips = Synchronizer.getInstance().inferiorChainSignatures;
+		return peerChainTipData == null || peerChainTipData.getSignature() == null || inferiorChainTips.contains(ByteArray.wrap(peerChainTipData.getSignature()));
+	};
+
 	public static final Predicate<Peer> hasOldVersion = peer -> {
 		final String minPeerVersion = Settings.getInstance().getMinPeerVersion();
 		return !peer.isAtLeastVersion(minPeerVersion);
@@ -952,6 +1073,18 @@ public class Controller extends Thread {
 		}
 	};
 
+	public static final Predicate<RNSPeer> hasInvalidSigner2 = peer -> {
+		final BlockSummaryData peerChainTipData = peer.getChainTipData();
+		if (peerChainTipData == null)
+			return true;
+
+		try (Repository repository = RepositoryManager.getRepository()) {
+			return Account.getRewardShareEffectiveMintingLevel(repository, peerChainTipData.getMinterPublicKey()) == 0;
+		} catch (DataException e) {
+			return true;
+		}
+	};
+
 	public static final Predicate<Peer> wasRecentlyTooDivergent = peer -> {
 		Long now = NTP.getTime();
 		Long peerLastTooDivergentTime = peer.getLastTooDivergentTime();
@@ -1105,6 +1238,7 @@ public class Controller extends Thread {
 
 				LOGGER.info("Shutting down synchronizer");
 				Synchronizer.getInstance().shutdown();
+				RNSSynchronizer.getInstance().shutdown();
 
 				LOGGER.info("Shutting down API");
 				ApiService.getInstance().stop();
@@ -1150,6 +1284,9 @@ public class Controller extends Thread {
 				LOGGER.info("Shutting down networking");
 				Network.getInstance().shutdown();
 
+				LOGGER.info("Shutting down Reticulum");
+				RNSNetwork.getInstance().shutdown();
+
 				LOGGER.info("Shutting down controller");
 				this.interrupt();
 				try {
@@ -1232,6 +1369,35 @@ public class Controller extends Thread {
 			network.broadcast(network::buildGetUnconfirmedTransactionsMessage);
 	}
 
+	public void doRNSNetworkBroadcast() {
+		if (Settings.getInstance().isLite()) {
+			// Lite nodes have nothing to broadcast
+			return;
+		}
+		RNSNetwork network = RNSNetwork.getInstance();
+
+		// Send our current height
+		network.broadcastOurChain();
+
+		// Request unconfirmed transaction signatures, but only if we're up-to-date.
+		// if we're not up-to-dat then priority is synchronizing first
+		if (isUpToDateRNS()) {
+			network.broadcast(network::buildGetUnconfirmedTransactionsMessage);
+		}
+
+	}
+
+	public void doRNSPrunePeers() {
+		RNSNetwork network = RNSNetwork.getInstance();
+
+        try {
+            LOGGER.debug("Pruning peers...");
+            network.prunePeers();
+        } catch (DataException e) {
+            LOGGER.warn(String.format("Repository issue when trying to prune peers: %s", e.getMessage()));
+        }
+	}
+
 	public void onMintingPossibleChange(boolean isMintingPossible) {
 		this.isMintingPossible = isMintingPossible;
 		requestSysTrayUpdate = true;
@@ -2163,4 +2329,688 @@ public class Controller extends Thread {
 	public StatsSnapshot getStatsSnapshot() {
 		return this.stats;
 	}
+
+	public void onRNSNetworkMessage(RNSPeer peer, Message message) {
+		LOGGER.trace(() -> String.format("Processing %s message from %s", message.getType().name(), peer));
+
+		// Ordered by message type value
+		switch (message.getType()) {
+			case GET_BLOCK:
+				onRNSNetworkGetBlockMessage(peer, message);
+				break;
+			
+			case GET_BLOCK_SUMMARIES:
+				onRNSNetworkGetBlockSummariesMessage(peer, message);
+				break;
+			
+			case GET_SIGNATURES_V2:
+				onRNSNetworkGetSignaturesV2Message(peer, message);
+				break;
+			
+			case HEIGHT_V2:
+				onRNSNetworkHeightV2Message(peer, message);
+				break;
+			
+			case BLOCK_SUMMARIES_V2:
+				onRNSNetworkBlockSummariesV2Message(peer, message);
+				break;
+			
+			case GET_TRANSACTION:
+				RNSTransactionImporter.getInstance().onNetworkGetTransactionMessage(peer, message);
+				break;
+			
+			case TRANSACTION:
+				RNSTransactionImporter.getInstance().onNetworkTransactionMessage(peer, message);
+				break;
+			
+			case GET_UNCONFIRMED_TRANSACTIONS:
+				RNSTransactionImporter.getInstance().onNetworkGetUnconfirmedTransactionsMessage(peer, message);
+				break;
+			
+			case TRANSACTION_SIGNATURES:
+				RNSTransactionImporter.getInstance().onNetworkTransactionSignaturesMessage(peer, message);
+				break;
+			
+			//case GET_ONLINE_ACCOUNTS_V3:
+			//	OnlineAccountsManager.getInstance().onNetworkGetOnlineAccountsV3Message(peer, message);
+			//	break;
+			//
+			//case ONLINE_ACCOUNTS_V3:
+			//	OnlineAccountsManager.getInstance().onNetworkOnlineAccountsV3Message(peer, message);
+			//	break;
+			
+			// TODO: Compiles but rethink for Reticulum
+			case GET_ARBITRARY_DATA:
+				// Not currently supported
+				break;
+
+			case ARBITRARY_DATA_FILE_LIST:
+				RNSArbitraryDataFileListManager.getInstance().onNetworkArbitraryDataFileListMessage(peer, message);
+				break;
+
+			case GET_ARBITRARY_DATA_FILE:
+				RNSArbitraryDataFileManager.getInstance().onNetworkGetArbitraryDataFileMessage(peer, message);
+				break;
+
+			case GET_ARBITRARY_DATA_FILE_LIST:
+				RNSArbitraryDataFileListManager.getInstance().onNetworkGetArbitraryDataFileListMessage(peer, message);
+				break;
+			//
+			case ARBITRARY_SIGNATURES:
+				// Not currently supported
+				break;
+			
+			case GET_ARBITRARY_METADATA:
+				RNSArbitraryMetadataManager.getInstance().onNetworkGetArbitraryMetadataMessage(peer, message);
+				break;
+			
+			case ARBITRARY_METADATA:
+				RNSArbitraryMetadataManager.getInstance().onNetworkArbitraryMetadataMessage(peer, message);
+				break;
+			
+			case GET_TRADE_PRESENCES:
+				RNSTradeBot.getInstance().onGetTradePresencesMessage(peer, message);
+				break;
+			
+			case TRADE_PRESENCES:
+				RNSTradeBot.getInstance().onTradePresencesMessage(peer, message);
+				break;
+			
+			case GET_ACCOUNT:
+				onRNSNetworkGetAccountMessage(peer, message);
+				break;
+			
+			case GET_ACCOUNT_BALANCE:
+				onRNSNetworkGetAccountBalanceMessage(peer, message);
+				break;
+			
+			case GET_ACCOUNT_TRANSACTIONS:
+				onRNSNetworkGetAccountTransactionsMessage(peer, message);
+				break;
+			
+			case GET_ACCOUNT_NAMES:
+				onRNSNetworkGetAccountNamesMessage(peer, message);
+				break;
+			
+			case GET_NAME:
+				onRNSNetworkGetNameMessage(peer, message);
+				break;
+
+			default:
+				LOGGER.debug(() -> String.format("Unhandled %s message [ID %d] from peer %s", message.getType().name(), message.getId(), peer));
+				break;
+		}
+	}
+
+	private void onRNSNetworkGetBlockMessage(RNSPeer peer, Message message) {
+		GetBlockMessage getBlockMessage = (GetBlockMessage) message;
+		byte[] signature = getBlockMessage.getSignature();
+		this.stats.getBlockMessageStats.requests.incrementAndGet();
+
+		ByteArray signatureAsByteArray = ByteArray.wrap(signature);
+
+		CachedBlockMessage cachedBlockMessage = this.blockMessageCache.get(signatureAsByteArray);
+		int blockCacheSize = Settings.getInstance().getBlockCacheSize();
+
+		// Check cached latest block message
+		if (cachedBlockMessage != null) {
+			this.stats.getBlockMessageStats.cacheHits.incrementAndGet();
+
+			// We need to duplicate it to prevent multiple threads setting ID on the same message
+			CachedBlockMessage clonedBlockMessage = Message.cloneWithNewId(cachedBlockMessage, message.getId());
+
+			//if (!peer.sendMessage(clonedBlockMessage))
+			//	peer.disconnect("failed to send block");
+			peer.sendMessage(clonedBlockMessage);
+
+			return;
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			BlockData blockData = repository.getBlockRepository().fromSignature(signature);
+
+			if (blockData != null) {
+				if (PruneManager.getInstance().isBlockPruned(blockData.getHeight())) {
+					// If this is a pruned block, we likely only have partial data, so best not to sent it
+					blockData = null;
+				}
+			}
+
+			// If we have no block data, we should check the archive in case it's there
+			if (blockData == null) {
+				if (Settings.getInstance().isArchiveEnabled()) {
+					Triple<byte[], Integer, Integer> serializedBlock = BlockArchiveReader.getInstance().fetchSerializedBlockBytesForSignature(signature, true, repository);
+					if (serializedBlock != null) {
+						byte[] bytes = serializedBlock.getA();
+						Integer serializationVersion = serializedBlock.getB();
+
+						Message blockMessage;
+						switch (serializationVersion) {
+							case 1:
+								blockMessage = new CachedBlockMessage(bytes);
+								break;
+
+							case 2:
+								blockMessage = new CachedBlockV2Message(bytes);
+								break;
+
+							default:
+								return;
+						}
+						blockMessage.setId(message.getId());
+
+						// This call also causes the other needed data to be pulled in from repository
+						//if (!peer.sendMessage(blockMessage)) {
+						//	peer.disconnect("failed to send block");
+						//	// Don't fall-through to caching because failure to send might be from failure to build message
+						//	return;
+						//}
+						peer.sendMessage(blockMessage);
+
+						// Sent successfully from archive, so nothing more to do
+						return;
+					}
+				}
+			}
+
+			if (blockData == null) {
+				// We don't have this block
+				this.stats.getBlockMessageStats.unknownBlocks.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer's synchronizer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'block unknown' response to peer %s for GET_BLOCK request for unknown block %s", peer, Base58.encode(signature)));
+
+				// Send generic 'unknown' message as it's very short
+				//Message blockUnknownMessage = peer.getPeersVersion() >= GenericUnknownMessage.MINIMUM_PEER_VERSION
+				//		? new GenericUnknownMessage()
+				//		: new BlockSummariesMessage(Collections.emptyList());
+				Message blockUnknownMessage = new GenericUnknownMessage();
+				blockUnknownMessage.setId(message.getId());
+				//if (!peer.sendMessage(blockUnknownMessage))
+				//	peer.disconnect("failed to send block-unknown response");
+				peer.sendMessage(blockUnknownMessage);
+				return;
+			}
+
+			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());
+
+			//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;
+			//}
+			peer.sendMessage(blockMessage);
+
+			// If request is for a recent block, cache it
+			if (getChainHeight() - blockData.getHeight() <= blockCacheSize) {
+				this.stats.getBlockMessageStats.cacheFills.incrementAndGet();
+
+				this.blockMessageCache.put(ByteArray.wrap(blockData.getSignature()), blockMessage);
+			}
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while sending block %s to peer %s", Base58.encode(signature), peer), e);
+		} catch (TransformationException e) {
+			LOGGER.error(String.format("Serialization issue while sending block %s to peer %s", Base58.encode(signature), peer), e);
+		}
+	}
+
+	private void onRNSNetworkGetBlockSummariesMessage(RNSPeer peer, Message message) {
+		GetBlockSummariesMessage getBlockSummariesMessage = (GetBlockSummariesMessage) message;
+		final byte[] parentSignature = getBlockSummariesMessage.getParentSignature();
+		this.stats.getBlockSummariesStats.requests.incrementAndGet();
+
+		// If peer's parent signature matches our latest block signature
+		// then we have no blocks after that and can short-circuit with an empty response
+		BlockData chainTip = getChainTip();
+		if (chainTip != null && Arrays.equals(parentSignature, chainTip.getSignature())) {
+			//Message blockSummariesMessage = peer.getPeersVersion() >= BlockSummariesV2Message.MINIMUM_PEER_VERSION
+			//		? new BlockSummariesV2Message(Collections.emptyList())
+			//		: new BlockSummariesMessage(Collections.emptyList());
+			Message blockSummariesMessage = new BlockSummariesV2Message(Collections.emptyList());
+
+			blockSummariesMessage.setId(message.getId());
+
+			//if (!peer.sendMessage(blockSummariesMessage))
+			//	peer.disconnect("failed to send block summaries");
+			peer.sendMessage(blockSummariesMessage);
+
+			return;
+		}
+
+		List<BlockSummaryData> blockSummaries = new ArrayList<>();
+
+		// Attempt to serve from our cache of latest blocks
+		synchronized (this.latestBlocks) {
+			blockSummaries = this.latestBlocks.stream()
+					.dropWhile(cachedBlockData -> !Arrays.equals(cachedBlockData.getReference(), parentSignature))
+					.map(BlockSummaryData::new)
+					.collect(Collectors.toList());
+		}
+
+		if (blockSummaries.isEmpty()) {
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int numberRequested = Math.min(Network.MAX_BLOCK_SUMMARIES_PER_REPLY, getBlockSummariesMessage.getNumberRequested());
+
+				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
+				if (blockData == null) {
+					// Try the archive
+					blockData = repository.getBlockArchiveRepository().fromReference(parentSignature);
+				}
+
+				if (blockData != null) {
+					if (PruneManager.getInstance().isBlockPruned(blockData.getHeight())) {
+						// If this request contains a pruned block, we likely only have partial data, so best not to sent anything
+						// We always prune from the oldest first, so it's fine to just check the first block requested
+						blockData = null;
+					}
+				}
+
+				while (blockData != null && blockSummaries.size() < numberRequested) {
+					BlockSummaryData blockSummary = new BlockSummaryData(blockData);
+					blockSummaries.add(blockSummary);
+
+					byte[] previousSignature = blockData.getSignature();
+					blockData = repository.getBlockRepository().fromReference(previousSignature);
+					if (blockData == null) {
+						// Try the archive
+						blockData = repository.getBlockArchiveRepository().fromReference(previousSignature);
+					}
+				}
+			} catch (DataException e) {
+				LOGGER.error(String.format("Repository issue while sending block summaries after %s to peer %s", Base58.encode(parentSignature), peer), e);
+			}
+		} else {
+			this.stats.getBlockSummariesStats.cacheHits.incrementAndGet();
+
+			if (blockSummaries.size() >= getBlockSummariesMessage.getNumberRequested())
+				this.stats.getBlockSummariesStats.fullyFromCache.incrementAndGet();
+		}
+
+		//Message blockSummariesMessage = peer.getPeersVersion() >= BlockSummariesV2Message.MINIMUM_PEER_VERSION
+		//		? new BlockSummariesV2Message(blockSummaries)
+		//		: new BlockSummariesMessage(blockSummaries);
+		Message blockSummariesMessage = new BlockSummariesV2Message(blockSummaries);
+		blockSummariesMessage.setId(message.getId());
+		//if (!peer.sendMessage(blockSummariesMessage))
+		//	peer.disconnect("failed to send block summaries");
+		peer.sendMessage(blockSummariesMessage);
+	}
+
+	private void onRNSNetworkGetSignaturesV2Message(RNSPeer peer, Message message) {
+		GetSignaturesV2Message getSignaturesMessage = (GetSignaturesV2Message) message;
+		final byte[] parentSignature = getSignaturesMessage.getParentSignature();
+		this.stats.getBlockSignaturesV2Stats.requests.incrementAndGet();
+
+		// If peer's parent signature matches our latest block signature
+		// then we can short-circuit with an empty response
+		BlockData chainTip = getChainTip();
+		if (chainTip != null && Arrays.equals(parentSignature, chainTip.getSignature())) {
+			Message signaturesMessage = new SignaturesMessage(Collections.emptyList());
+			signaturesMessage.setId(message.getId());
+			//if (!peer.sendMessage(signaturesMessage))
+			//	peer.disconnect("failed to send signatures (v2)");
+			peer.sendMessage(signaturesMessage);
+
+			return;
+		}
+
+		List<byte[]> signatures = new ArrayList<>();
+
+		// Attempt to serve from our cache of latest blocks
+		synchronized (this.latestBlocks) {
+			signatures = this.latestBlocks.stream()
+					.dropWhile(cachedBlockData -> !Arrays.equals(cachedBlockData.getReference(), parentSignature))
+					.map(BlockData::getSignature)
+					.collect(Collectors.toList());
+		}
+
+		if (signatures.isEmpty()) {
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int numberRequested = getSignaturesMessage.getNumberRequested();
+				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
+				if (blockData == null) {
+					// Try the archive
+					blockData = repository.getBlockArchiveRepository().fromReference(parentSignature);
+				}
+
+				while (blockData != null && signatures.size() < numberRequested) {
+					signatures.add(blockData.getSignature());
+
+					byte[] previousSignature = blockData.getSignature();
+					blockData = repository.getBlockRepository().fromReference(previousSignature);
+					if (blockData == null) {
+						// Try the archive
+						blockData = repository.getBlockArchiveRepository().fromReference(previousSignature);
+					}
+				}
+			} catch (DataException e) {
+				LOGGER.error(String.format("Repository issue while sending V2 signatures after %s to peer %s", Base58.encode(parentSignature), peer), e);
+			}
+		} else {
+			this.stats.getBlockSignaturesV2Stats.cacheHits.incrementAndGet();
+
+			if (signatures.size() >= getSignaturesMessage.getNumberRequested())
+				this.stats.getBlockSignaturesV2Stats.fullyFromCache.incrementAndGet();
+		}
+
+		Message signaturesMessage = new SignaturesMessage(signatures);
+		signaturesMessage.setId(message.getId());
+		//if (!peer.sendMessage(signaturesMessage))
+		//	peer.disconnect("failed to send signatures (v2)");
+		peer.sendMessage(signaturesMessage);
+	}
+
+	private void onRNSNetworkHeightV2Message(RNSPeer peer, Message message) {
+		HeightV2Message heightV2Message = (HeightV2Message) message;
+
+		if (!Settings.getInstance().isLite()) {
+			// If peer is inbound and we've not updated their height
+			// then this is probably their initial HEIGHT_V2 message
+			// so they need a corresponding HEIGHT_V2 message from us
+			if (!peer.getIsInitiator() && peer.getChainTipData() == null) {
+				Message responseMessage = RNSNetwork.getInstance().buildHeightOrChainTipInfo(peer);
+				peer.sendMessage(responseMessage);
+			}
+		}
+
+		// Update peer chain tip data
+		BlockSummaryData newChainTipData = new BlockSummaryData(heightV2Message.getHeight(), heightV2Message.getSignature(), heightV2Message.getMinterPublicKey(), heightV2Message.getTimestamp());
+		peer.setChainTipData(newChainTipData);
+
+		// Potentially synchronize
+		RNSSynchronizer.getInstance().requestSync();
+	}
+
+	private void onRNSNetworkBlockSummariesV2Message(RNSPeer peer, Message message) {
+		BlockSummariesV2Message blockSummariesV2Message = (BlockSummariesV2Message) message;
+
+		if (!Settings.getInstance().isLite()) {
+			//// If peer is inbound and we've not updated their height
+			//// then this is probably their initial BLOCK_SUMMARIES_V2 message
+			//// so they need a corresponding BLOCK_SUMMARIES_V2 message from us
+			if (!peer.getIsInitiator() && peer.getChainTipData() == null) {
+				Message responseMessage = RNSNetwork.getInstance().buildHeightOrChainTipInfo(peer);
+				peer.sendMessage(responseMessage);
+			}
+		}
+
+		if (message.hasId()) {
+			/*
+			 * Experimental proof-of-concept: discard messages with ID
+			 * These are 'late' reply messages received after timeout has expired,
+			 * having been passed upwards from Peer to Network to Controller.
+			 * Hence, these are NOT simple "here's my chain tip" broadcasts from other peers.
+			 */
+			LOGGER.debug("Discarding late {} message with ID {} from {}", message.getType().name(), message.getId(), peer);
+			return;
+		}
+
+		// Update peer chain tip data
+		peer.setChainTipSummaries(blockSummariesV2Message.getBlockSummaries());
+
+		// Potentially synchronize
+		RNSSynchronizer.getInstance().requestSync();
+	}
+
+	// ************
+
+	private void onRNSNetworkGetAccountMessage(RNSPeer peer, Message message) {
+		GetAccountMessage getAccountMessage = (GetAccountMessage) message;
+		String address = getAccountMessage.getAddress();
+		this.stats.getAccountMessageStats.requests.incrementAndGet();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+
+			if (accountData == null) {
+				// We don't have this account
+				this.stats.getAccountMessageStats.unknownAccounts.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'account unknown' response to peer %s for GET_ACCOUNT request for unknown account %s", peer, address));
+
+				// Send generic 'unknown' message as it's very short
+				Message accountUnknownMessage = new GenericUnknownMessage();
+				accountUnknownMessage.setId(message.getId());
+				peer.sendMessage(accountUnknownMessage);
+				return;
+			}
+
+			AccountMessage accountMessage = new AccountMessage(accountData);
+			accountMessage.setId(message.getId());
+
+			// handle in timeout callback instead
+			//if (!peer.sendMessage(accountMessage)) {
+			//	peer.disconnect("failed to send account");
+			//}
+			peer.sendMessage(accountMessage);
+
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while send account %s to peer %s", address, peer), e);
+		}
+	}
+
+	private void onRNSNetworkGetAccountBalanceMessage(RNSPeer peer, Message message) {
+		GetAccountBalanceMessage getAccountBalanceMessage = (GetAccountBalanceMessage) message;
+		String address = getAccountBalanceMessage.getAddress();
+		long assetId = getAccountBalanceMessage.getAssetId();
+		this.stats.getAccountBalanceMessageStats.requests.incrementAndGet();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			AccountBalanceData accountBalanceData = repository.getAccountRepository().getBalance(address, assetId);
+
+			if (accountBalanceData == null) {
+				// We don't have this account
+				this.stats.getAccountBalanceMessageStats.unknownAccounts.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'account unknown' response to peer %s for GET_ACCOUNT_BALANCE request for unknown account %s and asset ID %d", peer, address, assetId));
+
+				// Send generic 'unknown' message as it's very short
+				Message accountUnknownMessage = new GenericUnknownMessage();
+				accountUnknownMessage.setId(message.getId());
+				peer.sendMessage(accountUnknownMessage);
+				return;
+			}
+
+			AccountBalanceMessage accountMessage = new AccountBalanceMessage(accountBalanceData);
+			accountMessage.setId(message.getId());
+
+			// handle in timeout callback instead
+			//if (!peer.sendMessage(accountMessage)) {
+			//	peer.disconnect("failed to send account balance");
+			//}
+			peer.sendMessage(accountMessage);
+
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while send balance for account %s and asset ID %d to peer %s", address, assetId, peer), e);
+		}
+	}
+
+	private void onRNSNetworkGetAccountTransactionsMessage(RNSPeer peer, Message message) {
+		GetAccountTransactionsMessage getAccountTransactionsMessage = (GetAccountTransactionsMessage) message;
+		String address = getAccountTransactionsMessage.getAddress();
+		int limit = Math.min(getAccountTransactionsMessage.getLimit(), 100);
+		int offset = getAccountTransactionsMessage.getOffset();
+		this.stats.getAccountTransactionsMessageStats.requests.incrementAndGet();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<byte[]> signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(null, null, null,
+					null, null, null, address, TransactionsResource.ConfirmationStatus.CONFIRMED, limit, offset, false);
+
+			// Expand signatures to transactions
+			List<TransactionData> transactions = new ArrayList<>(signatures.size());
+			for (byte[] signature : signatures) {
+				transactions.add(repository.getTransactionRepository().fromSignature(signature));
+			}
+
+			if (transactions == null) {
+				// We don't have this account
+				this.stats.getAccountTransactionsMessageStats.unknownAccounts.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'account unknown' response to peer %s for GET_ACCOUNT_TRANSACTIONS request for unknown account %s", peer, address));
+
+				// Send generic 'unknown' message as it's very short
+				Message accountUnknownMessage = new GenericUnknownMessage();
+				accountUnknownMessage.setId(message.getId());
+				peer.sendMessage(accountUnknownMessage);
+				return;
+			}
+
+			TransactionsMessage transactionsMessage = new TransactionsMessage(transactions);
+			transactionsMessage.setId(message.getId());
+
+			// handle in timeout callback instead
+			//if (!peer.sendMessage(transactionsMessage)) {
+			//	peer.disconnect("failed to send account transactions");
+			//}
+			peer.sendMessage(transactionsMessage);
+
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while sending transactions for account %s %d to peer %s", address, peer), e);
+		} catch (MessageException e) {
+			LOGGER.error(String.format("Message serialization issue while sending transactions for account %s %d to peer %s", address, peer), e);
+		}
+	}
+
+	private void onRNSNetworkGetAccountNamesMessage(RNSPeer peer, Message message) {
+		GetAccountNamesMessage getAccountNamesMessage = (GetAccountNamesMessage) message;
+		String address = getAccountNamesMessage.getAddress();
+		this.stats.getAccountNamesMessageStats.requests.incrementAndGet();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<NameData> namesDataList = repository.getNameRepository().getNamesByOwner(address);
+
+			if (namesDataList == null) {
+				// We don't have this account
+				this.stats.getAccountNamesMessageStats.unknownAccounts.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'account unknown' response to peer %s for GET_ACCOUNT_NAMES request for unknown account %s", peer, address));
+
+				// Send generic 'unknown' message as it's very short
+				Message accountUnknownMessage = new GenericUnknownMessage();
+				accountUnknownMessage.setId(message.getId());
+				peer.sendMessage(accountUnknownMessage);
+				return;
+			}
+
+			NamesMessage namesMessage = new NamesMessage(namesDataList);
+			namesMessage.setId(message.getId());
+
+			// handle in timeout callback instead
+			//if (!peer.sendMessage(namesMessage)) {
+			//	peer.disconnect("failed to send account names");
+			//}
+			peer.sendMessage(namesMessage);
+
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while send names for account %s to peer %s", address, peer), e);
+		}
+	}
+
+	private void onRNSNetworkGetNameMessage(RNSPeer peer, Message message) {
+		GetNameMessage getNameMessage = (GetNameMessage) message;
+		String name = getNameMessage.getName();
+		this.stats.getNameMessageStats.requests.incrementAndGet();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			NameData nameData = repository.getNameRepository().fromName(name);
+
+			if (nameData == null) {
+				// We don't have this account
+				this.stats.getNameMessageStats.unknownAccounts.getAndIncrement();
+
+				// Send valid, yet unexpected message type in response, so peer doesn't have to wait for timeout
+				LOGGER.debug(() -> String.format("Sending 'name unknown' response to peer %s for GET_NAME request for unknown name %s", peer, name));
+
+				// Send generic 'unknown' message as it's very short
+				Message nameUnknownMessage = new GenericUnknownMessage();
+				nameUnknownMessage.setId(message.getId());
+				if (!peer.sendMessage(nameUnknownMessage))
+				peer.sendMessage(nameUnknownMessage);
+				return;
+			}
+
+			NamesMessage namesMessage = new NamesMessage(Arrays.asList(nameData));
+			namesMessage.setId(message.getId());
+
+			// handle in timeout callback instead
+			//if (!peer.sendMessage(namesMessage)) {
+			//	peer.disconnect("failed to send name data");
+			//}
+			peer.sendMessage(namesMessage);
+
+		} catch (DataException e) {
+			LOGGER.error(String.format("Repository issue while send name %s to peer %s", name, peer), e);
+		}
+	}
+
+	/**
+	 * Returns whether we think our node has up-to-date blockchain based on our info about other peers.
+	 * @param minLatestBlockTimestamp - the minimum block timestamp to be considered recent
+	 * @return boolean - whether our node's blockchain is up to date or not
+	 */
+	public boolean isUpToDateRNS(Long minLatestBlockTimestamp) {
+		if (Settings.getInstance().isLite()) {
+			// Lite nodes are always "up to date"
+			return true;
+		}
+
+		// Do we even have a vaguely recent block?
+		if (minLatestBlockTimestamp == null)
+			return false;
+
+		final BlockData latestBlockData = getChainTip();
+		if (latestBlockData == null || latestBlockData.getTimestamp() < minLatestBlockTimestamp)
+			return false;
+
+		if (Settings.getInstance().isSingleNodeTestnet())
+			// Single node testnets won't have peers, so we can assume up to date from this point
+			return true;
+
+		// Needs a mutable copy of the unmodifiableList
+		List<RNSPeer> peers = new ArrayList<>(RNSNetwork.getInstance().getActiveImmutableLinkedPeers());
+		if (peers == null)
+			return false;
+
+		//// Disregard peers that have "misbehaved" recently
+		//peers.removeIf(hasMisbehaved);
+		//
+		//// Disregard peers that don't have a recent block
+		//peers.removeIf(hasNoRecentBlock);
+
+		// Check we have enough peers to potentially synchronize/mint
+		if (peers.size() < Settings.getInstance().getReticulumMinDesiredPeers())
+			return false;
+
+		// If we don't have any peers left then can't synchronize, therefore consider ourself not up to date
+		return !peers.isEmpty();
+	}
+
+	/**
+	 * Returns whether we think our node has up-to-date blockchain based on our info about other peers.
+	 * Uses the default minLatestBlockTimestamp value.
+	 * @return boolean - whether our node's blockchain is up to date or not
+	 */
+	public boolean isUpToDateRNS() {
+		final Long minLatestBlockTimestamp = getMinimumLatestBlockTimestamp();
+		return this.isUpToDate(minLatestBlockTimestamp);
+	}
 }

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

@@ -0,0 +1,460 @@
+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.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.GetTransactionMessage;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.TransactionMessage;
+import org.qortal.network.message.TransactionSignaturesMessage;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.transaction.Transaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.util.*;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Collectors;
+
+public class RNSTransactionImporter extends Thread {
+
+    private static final Logger LOGGER = LogManager.getLogger(RNSTransactionImporter.class);
+
+    private static RNSTransactionImporter instance;
+    private volatile boolean isStopping = false;
+
+    private static final int MAX_INCOMING_TRANSACTIONS = 5000;
+
+    /** Minimum time before considering an invalid unconfirmed transaction as "stale" */
+    public static final long INVALID_TRANSACTION_STALE_TIMEOUT = 30 * 60 * 1000L; // ms
+    /** Minimum frequency to re-request stale unconfirmed transactions from peers, to recheck validity */
+    public static final long INVALID_TRANSACTION_RECHECK_INTERVAL = 60 * 60 * 1000L; // ms\
+    /** Minimum frequency to re-request expired unconfirmed transactions from peers, to recheck validity
+     * This mainly exists to stop expired transactions from bloating the list */
+    public static final long EXPIRED_TRANSACTION_RECHECK_INTERVAL = 10 * 60 * 1000L; // ms
+
+
+    /** Map of incoming transaction that are in the import queue. Key is transaction data, value is whether signature has been validated. */
+    private final Map<TransactionData, Boolean> incomingTransactions = Collections.synchronizedMap(new HashMap<>());
+
+    /** Map of recent invalid unconfirmed transactions. Key is base58 transaction signature, value is do-not-request expiry timestamp. */
+    private final Map<String, Long> invalidUnconfirmedTransactions = Collections.synchronizedMap(new HashMap<>());
+
+    /** Cached list of unconfirmed transactions, used when counting per creator. This is replaced regularly */
+    public static List<TransactionData> unconfirmedTransactionsCache = null;
+
+
+    public static synchronized RNSTransactionImporter getInstance() {
+        if (instance == null) {
+            instance = new RNSTransactionImporter();
+        }
+
+        return instance;
+    }
+
+    @Override
+    public void run() {
+        Thread.currentThread().setName("Transaction Importer");
+
+        try {
+            while (!Controller.isStopping()) {
+                Thread.sleep(500L);
+
+                // Process incoming transactions queue
+                validateTransactionsInQueue();
+                importTransactionsInQueue();
+
+                // Clean up invalid incoming transactions list
+                cleanupInvalidTransactionsList(NTP.getTime());
+            }
+        } catch (InterruptedException e) {
+            // Fall through to exit thread
+        }
+    }
+
+    public void shutdown() {
+        isStopping = true;
+        this.interrupt();
+    }
+
+
+    // Incoming transactions queue
+
+    private boolean incomingTransactionQueueContains(byte[] signature) {
+        synchronized (incomingTransactions) {
+            return incomingTransactions.keySet().stream().anyMatch(t -> Arrays.equals(t.getSignature(), signature));
+        }
+    }
+
+    private void removeIncomingTransaction(byte[] signature) {
+        incomingTransactions.keySet().removeIf(t -> Arrays.equals(t.getSignature(), signature));
+    }
+
+    /**
+     * Retrieve all pending unconfirmed transactions that have had their signatures validated.
+     * @return a list of TransactionData objects, with valid signatures.
+     */
+    private List<TransactionData> getCachedSigValidTransactions() {
+        synchronized (this.incomingTransactions) {
+            return this.incomingTransactions.entrySet().stream()
+                    .filter(t -> Boolean.TRUE.equals(t.getValue()))
+                    .map(Map.Entry::getKey)
+                    .collect(Collectors.toList());
+        }
+    }
+
+    /**
+     * Validate the signatures of any transactions pending import, then update their
+     * entries in the queue to mark them as valid/invalid.
+     *
+     * No database lock is required.
+     */
+    private void validateTransactionsInQueue() {
+        if (this.incomingTransactions.isEmpty()) {
+            // Nothing to do?
+            return;
+        }
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            // Take a snapshot of incomingTransactions, so we don't need to lock it while processing
+            Map<TransactionData, Boolean> incomingTransactionsCopy = Map.copyOf(this.incomingTransactions);
+
+            int unvalidatedCount = Collections.frequency(incomingTransactionsCopy.values(), Boolean.FALSE);
+            int validatedCount = 0;
+
+            if (unvalidatedCount > 0) {
+                LOGGER.debug("Validating signatures in incoming transactions queue (size {})...", unvalidatedCount);
+            }
+
+            // A list of all currently pending transactions that have valid signatures
+            List<Transaction> sigValidTransactions = new ArrayList<>();
+
+            // A list of signatures that became valid in this round
+            List<byte[]> newlyValidSignatures = new ArrayList<>();
+
+            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?
+                if (isStopping) {
+                    return;
+                }
+
+                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();
+                if (!Boolean.TRUE.equals(isSigValid)) {
+                    if (isLiteNode) {
+                        // Lite nodes can't easily validate transactions, so for now we will have to assume that everything is valid
+                        sigValidTransactions.add(transaction);
+                        newlyValidSignatures.add(transactionData.getSignature());
+                        // Add mark signature as valid if transaction still exists in import queue
+                        incomingTransactions.computeIfPresent(transactionData, (k, v) -> Boolean.TRUE);
+                        continue;
+                    }
+
+                    if (!transaction.isSignatureValid()) {
+                        LOGGER.debug("Ignoring {} transaction {} with invalid signature", transactionData.getType().name(), signature58);
+                        removeIncomingTransaction(transactionData.getSignature());
+
+                        // Also add to invalidIncomingTransactions map
+                        now = NTP.getTime();
+                        if (now != null) {
+                            Long expiry = now + INVALID_TRANSACTION_RECHECK_INTERVAL;
+                            LOGGER.trace("Adding invalid transaction {} to invalidUnconfirmedTransactions...", signature58);
+                            // Add to invalidUnconfirmedTransactions so that we don't keep requesting it
+                            invalidUnconfirmedTransactions.put(signature58, expiry);
+                        }
+
+                        // We're done with this transaction
+                        continue;
+                    }
+
+                    // Count the number that were validated in this round, for logging purposes
+                    validatedCount++;
+
+                    // Add mark signature as valid if transaction still exists in import queue
+                    incomingTransactions.computeIfPresent(transactionData, (k, v) -> Boolean.TRUE);
+
+                    // Signature validated in this round
+                    newlyValidSignatures.add(transactionData.getSignature());
+
+                } else {
+                    LOGGER.trace(() -> String.format("Transaction %s known to have valid signature", Base58.encode(transactionData.getSignature())));
+                }
+
+                // Signature valid - add to shortlist
+                sigValidTransactions.add(transaction);
+            }
+
+            if (unvalidatedCount > 0) {
+                LOGGER.debug("Finished validating signatures in incoming transactions queue (valid this round: {}, total pending import: {})...", validatedCount, sigValidTransactions.size());
+            }
+
+        } catch (DataException e) {
+            LOGGER.error("Repository issue while processing incoming transactions", e);
+        }
+    }
+
+    /**
+     * Import any transactions in the queue that have valid signatures.
+     *
+     * A database lock is required.
+     */
+    private void importTransactionsInQueue() {
+        List<TransactionData> sigValidTransactions = this.getCachedSigValidTransactions();
+        if (sigValidTransactions.isEmpty()) {
+            // Don't bother locking if there are no new transactions to process
+            return;
+        }
+
+        if (Synchronizer.getInstance().isSyncRequested() || Synchronizer.getInstance().isSynchronizing()) {
+            // Prioritize syncing, and don't attempt to lock
+            return;
+        }
+
+        ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+        if (!blockchainLock.tryLock()) {
+            LOGGER.debug("Too busy to import incoming transactions queue");
+            return;
+        }
+
+        LOGGER.debug("Importing incoming transactions queue (size {})...", sigValidTransactions.size());
+
+        int processedCount = 0;
+        try (final Repository repository = RepositoryManager.getRepository()) {
+
+            // Use a single copy of the unconfirmed transactions list for each cycle, to speed up constant lookups
+            // when counting unconfirmed transactions by creator.
+            List<TransactionData> unconfirmedTransactions = repository.getTransactionRepository().getUnconfirmedTransactions();
+            unconfirmedTransactions.removeIf(t -> t.getType() == Transaction.TransactionType.CHAT);
+            unconfirmedTransactionsCache = unconfirmedTransactions;
+
+            // A list of signatures were imported in this round
+            List<byte[]> newlyImportedSignatures = new ArrayList<>();
+
+            // Import transactions with valid signatures
+            try {
+                for (int i = 0; i < sigValidTransactions.size(); ++i) {
+                    if (isStopping) {
+                        return;
+                    }
+
+                    if (Synchronizer.getInstance().isSyncRequestPending()) {
+                        LOGGER.debug("Breaking out of transaction importing with {} remaining, because a sync request is pending", sigValidTransactions.size() - i);
+                        return;
+                    }
+
+                    TransactionData transactionData = sigValidTransactions.get(i);
+                    Transaction transaction = Transaction.fromData(repository, transactionData);
+
+                    Transaction.ValidationResult validationResult = transaction.importAsUnconfirmed();
+                    processedCount++;
+
+                    switch (validationResult) {
+                        case TRANSACTION_ALREADY_EXISTS: {
+                            LOGGER.trace(() -> String.format("Ignoring existing transaction %s", Base58.encode(transactionData.getSignature())));
+                            break;
+                        }
+
+                        case NO_BLOCKCHAIN_LOCK: {
+                            // Is this even possible considering we acquired blockchain lock above?
+                            LOGGER.trace(() -> String.format("Couldn't lock blockchain to import unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
+                            break;
+                        }
+
+                        case OK: {
+                            LOGGER.debug(() -> String.format("Imported %s transaction %s", transactionData.getType().name(), Base58.encode(transactionData.getSignature())));
+
+                            // Add to the unconfirmed transactions cache
+                            if (transactionData.getType() != Transaction.TransactionType.CHAT && unconfirmedTransactionsCache != null) {
+                                unconfirmedTransactionsCache.add(transactionData);
+                            }
+
+                            // Signature imported in this round
+                            newlyImportedSignatures.add(transactionData.getSignature());
+
+                            break;
+                        }
+
+                        // All other invalid cases:
+                        default: {
+                            final String signature58 = Base58.encode(transactionData.getSignature());
+                            LOGGER.debug(() -> String.format("Ignoring invalid (%s) %s transaction %s", validationResult.name(), transactionData.getType().name(), signature58));
+
+                            Long now = NTP.getTime();
+                            if (now != null && now - transactionData.getTimestamp() > INVALID_TRANSACTION_STALE_TIMEOUT) {
+                                Long expiryLength = INVALID_TRANSACTION_RECHECK_INTERVAL;
+
+                                if (validationResult == Transaction.ValidationResult.TIMESTAMP_TOO_OLD) {
+                                    // Use shorter recheck interval for expired transactions
+                                    expiryLength = EXPIRED_TRANSACTION_RECHECK_INTERVAL;
+                                }
+
+                                Long expiry = now + expiryLength;
+                                LOGGER.trace("Adding stale invalid transaction {} to invalidUnconfirmedTransactions...", signature58);
+                                // Invalid, unconfirmed transaction has become stale - add to invalidUnconfirmedTransactions so that we don't keep requesting it
+                                invalidUnconfirmedTransactions.put(signature58, expiry);
+                            }
+                        }
+                    }
+
+                    // Transaction has been processed, even if only to reject it
+                    removeIncomingTransaction(transactionData.getSignature());
+                }
+
+                if (!newlyImportedSignatures.isEmpty()) {
+                    LOGGER.debug("Broadcasting {} newly imported signatures", newlyImportedSignatures.size());
+                    Message newTransactionSignatureMessage = new TransactionSignaturesMessage(newlyImportedSignatures);
+                    RNSNetwork.getInstance().broadcast(broadcastPeer -> newTransactionSignatureMessage);
+                }
+            } finally {
+                LOGGER.debug("Finished importing {} incoming transaction{}", processedCount, (processedCount == 1 ? "" : "s"));
+                blockchainLock.unlock();
+
+                // Clear the unconfirmed transaction cache so new data can be populated in the next cycle
+                unconfirmedTransactionsCache = null;
+            }
+        } catch (DataException e) {
+            LOGGER.error("Repository issue while importing incoming transactions", e);
+        }
+    }
+
+    private void cleanupInvalidTransactionsList(Long now) {
+        if (now == null) {
+            return;
+        }
+        // Periodically remove invalid unconfirmed transactions from the list, so that they can be fetched again
+        invalidUnconfirmedTransactions.entrySet().removeIf(entry -> entry.getValue() == null || entry.getValue() < now);
+    }
+
+
+    // Network handlers
+
+    public void onNetworkTransactionMessage(RNSPeer peer, Message message) {
+        TransactionMessage transactionMessage = (TransactionMessage) message;
+        TransactionData transactionData = transactionMessage.getTransactionData();
+
+        if (this.incomingTransactions.size() < MAX_INCOMING_TRANSACTIONS) {
+            synchronized (this.incomingTransactions) {
+                if (!incomingTransactionQueueContains(transactionData.getSignature())) {
+                    this.incomingTransactions.put(transactionData, Boolean.FALSE);
+                }
+            }
+        }
+    }
+
+    public void onNetworkGetTransactionMessage(RNSPeer peer, Message message) {
+        GetTransactionMessage getTransactionMessage = (GetTransactionMessage) message;
+        byte[] signature = getTransactionMessage.getSignature();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            // Firstly check the sig-valid transactions that are currently queued for import
+            TransactionData transactionData = this.getCachedSigValidTransactions().stream()
+                    .filter(t -> Arrays.equals(signature, t.getSignature()))
+                    .findFirst().orElse(null);
+
+            if (transactionData == null) {
+                // Not found in import queue, so try the database
+                transactionData = repository.getTransactionRepository().fromSignature(signature);
+            }
+
+            if (transactionData == null) {
+                // Still not found - so we don't have this transaction
+                LOGGER.debug(() -> String.format("Ignoring GET_TRANSACTION request from peer %s for unknown transaction %s", peer, Base58.encode(signature)));
+                // Send no response at all???
+                return;
+            }
+
+            Message transactionMessage = new TransactionMessage(transactionData);
+            transactionMessage.setId(message.getId());
+            peer.sendMessage(transactionMessage);
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while sending transaction %s to peer %s", Base58.encode(signature), peer), e);
+        } catch (TransformationException e) {
+            LOGGER.error(String.format("Serialization issue while sending transaction %s to peer %s", Base58.encode(signature), peer), e);
+        }
+    }
+
+    public void onNetworkGetUnconfirmedTransactionsMessage(RNSPeer peer, Message message) {
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            List<byte[]> signatures = Collections.emptyList();
+
+            // If we're NOT up-to-date then don't send out unconfirmed transactions
+            // as it's possible they are already included in a later block that we don't have.
+            if (Controller.getInstance().isUpToDate())
+                signatures = repository.getTransactionRepository().getUnconfirmedTransactionSignatures();
+
+            Message transactionSignaturesMessage = new TransactionSignaturesMessage(signatures);
+            peer.sendMessage(transactionSignaturesMessage);
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while sending unconfirmed transaction signatures to peer %s", peer), e);
+        }
+    }
+
+    public void onNetworkTransactionSignaturesMessage(RNSPeer peer, Message message) {
+        TransactionSignaturesMessage transactionSignaturesMessage = (TransactionSignaturesMessage) message;
+        List<byte[]> signatures = transactionSignaturesMessage.getSignatures();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            for (byte[] signature : signatures) {
+                String signature58 = Base58.encode(signature);
+                if (invalidUnconfirmedTransactions.containsKey(signature58)) {
+                    // Previously invalid transaction - don't keep requesting it
+                    // It will be periodically removed from invalidUnconfirmedTransactions to allow for rechecks
+                    continue;
+                }
+
+                // Ignore if this transaction is in the queue
+                if (incomingTransactionQueueContains(signature)) {
+                    LOGGER.trace(() -> String.format("Ignoring existing queued transaction %s from peer %s", Base58.encode(signature), peer));
+                    continue;
+                }
+
+                // Do we have it already? (Before requesting transaction data itself)
+                if (repository.getTransactionRepository().exists(signature)) {
+                    LOGGER.trace(() -> String.format("Ignoring existing transaction %s from peer %s", Base58.encode(signature), peer));
+                    continue;
+                }
+
+                // Check isInterrupted() here and exit fast
+                if (Thread.currentThread().isInterrupted())
+                    return;
+
+                // Fetch actual transaction data from peer
+                Message getTransactionMessage = new GetTransactionMessage(signature);
+                peer.sendMessage(getTransactionMessage);
+            }
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while processing unconfirmed transactions from peer %s", peer), e);
+        }
+    }
+
+}

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

@@ -0,0 +1,731 @@
+package org.qortal.controller.arbitrary;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.arbitrary.ArbitraryDataFile;
+import org.qortal.arbitrary.ArbitraryDataFileChunk;
+import org.qortal.controller.Controller;
+import org.qortal.data.arbitrary.RNSArbitraryDirectConnectionInfo;
+import org.qortal.data.arbitrary.RNSArbitraryFileListResponseInfo;
+import org.qortal.data.arbitrary.RNSArbitraryRelayInfo;
+import org.qortal.data.transaction.ArbitraryTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.ArbitraryDataFileListMessage;
+import org.qortal.network.message.GetArbitraryDataFileListMessage;
+import org.qortal.network.message.Message;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.utils.Base58;
+import org.qortal.utils.ListUtils;
+import org.qortal.utils.NTP;
+import org.qortal.utils.Triple;
+
+import java.util.*;
+
+import static org.qortal.controller.arbitrary.RNSArbitraryDataFileManager.MAX_FILE_HASH_RESPONSES;
+
+public class RNSArbitraryDataFileListManager {
+
+    private static final Logger LOGGER = LogManager.getLogger(RNSArbitraryDataFileListManager.class);
+
+    private static RNSArbitraryDataFileListManager instance;
+
+    private static String MIN_PEER_VERSION_FOR_FILE_LIST_STATS = "3.2.0";
+
+    /**
+     * Map of recent incoming requests for ARBITRARY transaction data file lists.
+     * <p>
+     * Key is original request's message ID<br>
+     * Value is Triple&lt;transaction signature in base58, first requesting peer, first request's timestamp&gt;
+     * <p>
+     * If peer is null then either:<br>
+     * <ul>
+     * <li>we are the original requesting peer</li>
+     * <li>we have already sent data payload to original requesting peer.</li>
+     * </ul>
+     * If signature is null then we have already received the file list and either:<br>
+     * <ul>
+     * <li>we are the original requesting peer and have processed it</li>
+     * <li>we have forwarded the file list</li>
+     * </ul>
+     */
+    public Map<Integer, Triple<String, RNSPeer, Long>> arbitraryDataFileListRequests = Collections.synchronizedMap(new HashMap<>());
+
+    /**
+     * Map to keep track of in progress arbitrary data signature requests
+     * Key: string - the signature encoded in base58
+     * Value: Triple<networkBroadcastCount, directPeerRequestCount, lastAttemptTimestamp>
+     */
+    private Map<String, Triple<Integer, Integer, Long>> arbitraryDataSignatureRequests = Collections.synchronizedMap(new HashMap<>());
+
+
+    /** Maximum number of seconds that a file list relay request is able to exist on the network */
+    public static long RELAY_REQUEST_MAX_DURATION = 5000L;
+    /** Maximum number of hops that a file list relay request is allowed to make */
+    public static int RELAY_REQUEST_MAX_HOPS = 4;
+
+    /** Minimum peer version to use relay */
+    public static String RELAY_MIN_PEER_VERSION = "3.4.0";
+
+
+    private RNSArbitraryDataFileListManager() {
+    }
+
+    public static RNSArbitraryDataFileListManager getInstance() {
+        if (instance == null)
+            instance = new RNSArbitraryDataFileListManager();
+
+        return instance;
+    }
+
+
+    public void cleanupRequestCache(Long now) {
+        if (now == null) {
+            return;
+        }
+        final long requestMinimumTimestamp = now - ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT;
+        arbitraryDataFileListRequests.entrySet().removeIf(entry -> entry.getValue().getC() == null || entry.getValue().getC() < requestMinimumTimestamp);
+    }
+
+
+    // Track file list lookups by signature
+
+    private boolean shouldMakeFileListRequestForSignature(String signature58) {
+        Triple<Integer, Integer, Long> request = arbitraryDataSignatureRequests.get(signature58);
+
+        if (request == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        // Extract the components
+        Integer networkBroadcastCount = request.getA();
+        // Integer directPeerRequestCount = request.getB();
+        Long lastAttemptTimestamp = request.getC();
+
+        if (lastAttemptTimestamp == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        long timeSinceLastAttempt = NTP.getTime() - lastAttemptTimestamp;
+
+        // Allow a second attempt after 15 seconds, and another after 30 seconds
+        if (timeSinceLastAttempt > 15 * 1000L) {
+            // We haven't tried for at least 15 seconds
+
+            if (networkBroadcastCount < 3) {
+                // We've made less than 3 total attempts
+                return true;
+            }
+        }
+
+        // Then allow another 5 attempts, each 1 minute apart
+        if (timeSinceLastAttempt > 60 * 1000L) {
+            // We haven't tried for at least 1 minute
+
+            if (networkBroadcastCount < 8) {
+                // We've made less than 8 total attempts
+                return true;
+            }
+        }
+
+        // Then allow another 8 attempts, each 15 minutes apart
+        if (timeSinceLastAttempt > 15 * 60 * 1000L) {
+            // We haven't tried for at least 15 minutes
+
+            if (networkBroadcastCount < 16) {
+                // We've made less than 16 total attempts
+                return true;
+            }
+        }
+
+        // From then on, only try once every 6 hours, to reduce network spam
+        if (timeSinceLastAttempt > 6 * 60 * 60 * 1000L) {
+            // We haven't tried for at least 6 hours
+            return true;
+        }
+
+        return false;
+    }
+
+    private boolean shouldMakeDirectFileRequestsForSignature(String signature58) {
+        if (!Settings.getInstance().isDirectDataRetrievalEnabled()) {
+            // Direct connections are disabled in the settings
+            return false;
+        }
+
+        Triple<Integer, Integer, Long> request = arbitraryDataSignatureRequests.get(signature58);
+
+        if (request == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        // Extract the components
+        //Integer networkBroadcastCount = request.getA();
+        Integer directPeerRequestCount = request.getB();
+        Long lastAttemptTimestamp = request.getC();
+
+        if (lastAttemptTimestamp == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        if (directPeerRequestCount == 0) {
+            // We haven't tried asking peers directly yet, so we should
+            return true;
+        }
+
+        long timeSinceLastAttempt = NTP.getTime() - lastAttemptTimestamp;
+        if (timeSinceLastAttempt > 10 * 1000L) {
+            // We haven't tried for at least 10 seconds
+            if (directPeerRequestCount < 5) {
+                // We've made less than 5 total attempts
+                return true;
+            }
+        }
+
+        if (timeSinceLastAttempt > 5 * 60 * 1000L) {
+            // We haven't tried for at least 5 minutes
+            if (directPeerRequestCount < 10) {
+                // We've made less than 10 total attempts
+                return true;
+            }
+        }
+
+        if (timeSinceLastAttempt > 60 * 60 * 1000L) {
+            // We haven't tried for at least 1 hour
+            return true;
+        }
+
+        return false;
+    }
+
+    public boolean isSignatureRateLimited(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+        return !this.shouldMakeFileListRequestForSignature(signature58)
+                && !this.shouldMakeDirectFileRequestsForSignature(signature58);
+    }
+
+    public long lastRequestForSignature(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+        Triple<Integer, Integer, Long> request = arbitraryDataSignatureRequests.get(signature58);
+
+        if (request == null) {
+            // Not attempted yet
+            return 0;
+        }
+
+        // Extract the components
+        Long lastAttemptTimestamp = request.getC();
+        if (lastAttemptTimestamp != null) {
+            return  lastAttemptTimestamp;
+        }
+        return 0;
+    }
+
+    public void addToSignatureRequests(String signature58, boolean incrementNetworkRequests, boolean incrementPeerRequests) {
+        Triple<Integer, Integer, Long> request  = arbitraryDataSignatureRequests.get(signature58);
+        Long now = NTP.getTime();
+
+        if (request == null) {
+            // No entry yet
+            Triple<Integer, Integer, Long> newRequest = new Triple<>(0, 0, now);
+            arbitraryDataSignatureRequests.put(signature58, newRequest);
+        }
+        else {
+            // There is an existing entry
+            if (incrementNetworkRequests) {
+                request.setA(request.getA() + 1);
+            }
+            if (incrementPeerRequests) {
+                request.setB(request.getB() + 1);
+            }
+            request.setC(now);
+            arbitraryDataSignatureRequests.put(signature58, request);
+        }
+    }
+
+    public void removeFromSignatureRequests(String signature58) {
+        arbitraryDataSignatureRequests.remove(signature58);
+    }
+
+
+    // Lookup file lists by signature (and optionally hashes)
+
+    public boolean fetchArbitraryDataFileList(ArbitraryTransactionData arbitraryTransactionData) {
+        byte[] signature = arbitraryTransactionData.getSignature();
+        String signature58 = Base58.encode(signature);
+
+        // Require an NTP sync
+        Long now = NTP.getTime();
+        if (now == null) {
+            return false;
+        }
+
+        // If we've already tried too many times in a short space of time, make sure to give up
+        if (!this.shouldMakeFileListRequestForSignature(signature58)) {
+            // Check if we should make direct connections to peers
+            if (this.shouldMakeDirectFileRequestsForSignature(signature58)) {
+                return RNSArbitraryDataFileManager.getInstance().fetchDataFilesFromPeersForSignature(signature);
+            }
+
+            LOGGER.trace("Skipping file list request for signature {} due to rate limit", signature58);
+            return false;
+        }
+        this.addToSignatureRequests(signature58, true, false);
+
+        //List<Peer> handshakedPeers = Network.getInstance().getImmutableHandshakedPeers();
+        List<RNSPeer> handshakedPeers = RNSNetwork.getInstance().getLinkedPeers();
+        List<byte[]> missingHashes = null;
+
+        // Find hashes that we are missing
+        try {
+            ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
+            missingHashes = arbitraryDataFile.missingHashes();
+        } catch (DataException e) {
+            // Leave missingHashes as null, so that all hashes are requested
+        }
+        int hashCount = missingHashes != null ? missingHashes.size() : 0;
+
+        LOGGER.debug(String.format("Sending data file list request for signature %s with %d hashes to %d peers...", signature58, hashCount, handshakedPeers.size()));
+
+        //// Send our address as requestingPeer, to allow for potential direct connections with seeds/peers
+        //String requestingPeer = Network.getInstance().getOurExternalIpAddressAndPort();
+        String requestingPeer = null;
+
+        // Build request
+        Message getArbitraryDataFileListMessage = new GetArbitraryDataFileListMessage(signature, missingHashes, now, 0, requestingPeer);
+
+        // Save our request into requests map
+        Triple<String, RNSPeer, Long> requestEntry = new Triple<>(signature58, null, NTP.getTime());
+
+        // Assign random ID to this message
+        int id;
+        do {
+            id = new Random().nextInt(Integer.MAX_VALUE - 1) + 1;
+
+            // Put queue into map (keyed by message ID) so we can poll for a response
+            // If putIfAbsent() doesn't return null, then this ID is already taken
+        } while (arbitraryDataFileListRequests.put(id, requestEntry) != null);
+        getArbitraryDataFileListMessage.setId(id);
+
+        // Broadcast request
+        RNSNetwork.getInstance().broadcast(peer -> getArbitraryDataFileListMessage);
+
+        // Poll to see if data has arrived
+        final long singleWait = 100;
+        long totalWait = 0;
+        while (totalWait < ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT) {
+            try {
+                Thread.sleep(singleWait);
+            } catch (InterruptedException e) {
+                break;
+            }
+
+            requestEntry = arbitraryDataFileListRequests.get(id);
+            if (requestEntry == null)
+                return false;
+
+            if (requestEntry.getA() == null)
+                break;
+
+            totalWait += singleWait;
+        }
+        return true;
+    }
+
+    public boolean fetchArbitraryDataFileList(RNSPeer peer, byte[] signature) {
+        String signature58 = Base58.encode(signature);
+
+        // Require an NTP sync
+        Long now = NTP.getTime();
+        if (now == null) {
+            return false;
+        }
+
+        int hashCount = 0;
+        LOGGER.debug(String.format("Sending data file list request for signature %s with %d hashes to peer %s...", signature58, hashCount, peer));
+
+        // Build request
+        // Use a time in the past, so that the recipient peer doesn't try and relay it
+        // Also, set hashes to null since it's easier to request all hashes than it is to determine which ones we need
+        // This could be optimized in the future
+        long timestamp = now - 60000L;
+        List<byte[]> hashes = null;
+        Message getArbitraryDataFileListMessage = new GetArbitraryDataFileListMessage(signature, hashes, timestamp, 0, null);
+
+        // Save our request into requests map
+        Triple<String, RNSPeer, Long> requestEntry = new Triple<>(signature58, null, NTP.getTime());
+
+        // Assign random ID to this message
+        int id;
+        do {
+            id = new Random().nextInt(Integer.MAX_VALUE - 1) + 1;
+
+            // Put queue into map (keyed by message ID) so we can poll for a response
+            // If putIfAbsent() doesn't return null, then this ID is already taken
+        } while (arbitraryDataFileListRequests.put(id, requestEntry) != null);
+        getArbitraryDataFileListMessage.setId(id);
+
+        // Send the request
+        peer.sendMessage(getArbitraryDataFileListMessage);
+
+        // Poll to see if data has arrived
+        final long singleWait = 100;
+        long totalWait = 0;
+        while (totalWait < ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT) {
+            try {
+                Thread.sleep(singleWait);
+            } catch (InterruptedException e) {
+                break;
+            }
+
+            requestEntry = arbitraryDataFileListRequests.get(id);
+            if (requestEntry == null)
+                return false;
+
+            if (requestEntry.getA() == null)
+                break;
+
+            totalWait += singleWait;
+        }
+        return true;
+    }
+
+    public void deleteFileListRequestsForSignature(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+        for (Iterator<Map.Entry<Integer, Triple<String, RNSPeer, Long>>> it = arbitraryDataFileListRequests.entrySet().iterator(); it.hasNext();) {
+            Map.Entry<Integer, Triple<String, RNSPeer, Long>> entry = it.next();
+            if (entry == null || entry.getKey() == null || entry.getValue() != null) {
+                continue;
+            }
+            if (Objects.equals(entry.getValue().getA(), signature58)) {
+                // Update requests map to reflect that we've received all chunks
+                Triple<String, RNSPeer, Long> newEntry = new Triple<>(null, null, entry.getValue().getC());
+                arbitraryDataFileListRequests.put(entry.getKey(), newEntry);
+            }
+        }
+    }
+
+    // Network handlers
+
+    public void onNetworkArbitraryDataFileListMessage(RNSPeer peer, Message message) {
+        // Don't process if QDN is disabled
+        if (!Settings.getInstance().isQdnEnabled()) {
+            return;
+        }
+
+        ArbitraryDataFileListMessage arbitraryDataFileListMessage = (ArbitraryDataFileListMessage) message;
+        LOGGER.debug("Received hash list from peer {} with {} hashes", peer, arbitraryDataFileListMessage.getHashes().size());
+
+        if (LOGGER.isDebugEnabled() && arbitraryDataFileListMessage.getRequestTime() != null) {
+            long totalRequestTime = NTP.getTime() - arbitraryDataFileListMessage.getRequestTime();
+            LOGGER.debug("totalRequestTime: {}, requestHops: {}, peerAddress: {}, isRelayPossible: {}",
+                    totalRequestTime, arbitraryDataFileListMessage.getRequestHops(),
+                    arbitraryDataFileListMessage.getPeerAddress(), arbitraryDataFileListMessage.isRelayPossible());
+        }
+
+        // Do we have a pending request for this data?
+        Triple<String, RNSPeer, Long> request = arbitraryDataFileListRequests.get(message.getId());
+        if (request == null || request.getA() == null) {
+            return;
+        }
+        boolean isRelayRequest = (request.getB() != null);
+
+        // Does this message's signature match what we're expecting?
+        byte[] signature = arbitraryDataFileListMessage.getSignature();
+        String signature58 = Base58.encode(signature);
+        if (!request.getA().equals(signature58)) {
+            return;
+        }
+
+        List<byte[]> hashes = arbitraryDataFileListMessage.getHashes();
+        if (hashes == null || hashes.isEmpty()) {
+            return;
+        }
+
+        ArbitraryTransactionData arbitraryTransactionData = null;
+
+        // Check transaction exists and hashes are correct
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            TransactionData transactionData = repository.getTransactionRepository().fromSignature(signature);
+            if (!(transactionData instanceof ArbitraryTransactionData))
+                return;
+
+            arbitraryTransactionData = (ArbitraryTransactionData) transactionData;
+
+//          // Load data file(s)
+//          ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
+//
+//			// Check all hashes exist
+//			for (byte[] hash : hashes) {
+//				//LOGGER.debug("Received hash {}", Base58.encode(hash));
+//				if (!arbitraryDataFile.containsChunk(hash)) {
+//					// Check the hash against the complete file
+//					if (!Arrays.equals(arbitraryDataFile.getHash(), hash)) {
+//						LOGGER.info("Received non-matching chunk hash {} for signature {}. This could happen if we haven't obtained the metadata file yet.", Base58.encode(hash), signature58);
+//						return;
+//					}
+//				}
+//			}
+
+            if (!isRelayRequest || !Settings.getInstance().isRelayModeEnabled()) {
+                Long now = NTP.getTime();
+
+                if (RNSArbitraryDataFileManager.getInstance().arbitraryDataFileHashResponses.size() < MAX_FILE_HASH_RESPONSES) {
+                    // Keep track of the hashes this peer reports to have access to
+                    for (byte[] hash : hashes) {
+                        String hash58 = Base58.encode(hash);
+
+                        // Treat null request hops as 100, so that they are able to be sorted (and put to the end of the list)
+                        int requestHops = arbitraryDataFileListMessage.getRequestHops() != null ? arbitraryDataFileListMessage.getRequestHops() : 100;
+
+                        RNSArbitraryFileListResponseInfo responseInfo = new RNSArbitraryFileListResponseInfo(hash58, signature58,
+                                peer, now, arbitraryDataFileListMessage.getRequestTime(), requestHops);
+
+                        RNSArbitraryDataFileManager.getInstance().arbitraryDataFileHashResponses.add(responseInfo);
+                    }
+                }
+
+                // Keep track of the source peer, for direct connections
+                if (arbitraryDataFileListMessage.getPeerAddress() != null) {
+                    RNSArbitraryDataFileManager.getInstance().addDirectConnectionInfoIfUnique(
+                            new RNSArbitraryDirectConnectionInfo(signature, arbitraryDataFileListMessage.getPeerAddress(), hashes, now));
+                }
+            }
+
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while finding arbitrary transaction data list for peer %s", peer), e);
+        }
+
+        // Forwarding
+        if (isRelayRequest && Settings.getInstance().isRelayModeEnabled()) {
+            boolean isBlocked = (arbitraryTransactionData == null || ListUtils.isNameBlocked(arbitraryTransactionData.getName()));
+            if (!isBlocked) {
+                RNSPeer requestingPeer = request.getB();
+                if (requestingPeer != null) {
+                    Long requestTime = arbitraryDataFileListMessage.getRequestTime();
+                    Integer requestHops = arbitraryDataFileListMessage.getRequestHops();
+
+                    // Add each hash to our local mapping so we know who to ask later
+                    Long now = NTP.getTime();
+                    for (byte[] hash : hashes) {
+                        String hash58 = Base58.encode(hash);
+                        RNSArbitraryRelayInfo relayInfo = new RNSArbitraryRelayInfo(hash58, signature58, peer, now, requestTime, requestHops);
+                        RNSArbitraryDataFileManager.getInstance().addToRelayMap(relayInfo);
+                    }
+
+                    // Bump requestHops if it exists
+                    if (requestHops != null) {
+                        requestHops++;
+                    }
+
+                    ArbitraryDataFileListMessage forwardArbitraryDataFileListMessage;
+
+                    //// TODO - rework for Reticulum
+                    //// Remove optional parameters if the requesting peer doesn't support it yet
+                    //// A message with less statistical data is better than no message at all
+                    //if (!requestingPeer.isAtLeastVersion(MIN_PEER_VERSION_FOR_FILE_LIST_STATS)) {
+                    //    forwardArbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes);
+                    //} else {
+                    //    forwardArbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes, requestTime, requestHops,
+                    //            arbitraryDataFileListMessage.getPeerAddress(), arbitraryDataFileListMessage.isRelayPossible());
+                    //}
+                    forwardArbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes, requestTime, requestHops,
+                            arbitraryDataFileListMessage.getPeerAddress(), arbitraryDataFileListMessage.isRelayPossible());
+                    forwardArbitraryDataFileListMessage.setId(message.getId());
+
+                    // Forward to requesting peer
+                    LOGGER.debug("Forwarding file list with {} hashes to requesting peer: {}", hashes.size(), requestingPeer);
+                    //if (!requestingPeer.sendMessage(forwardArbitraryDataFileListMessage)) {
+                    //    requestingPeer.disconnect("failed to forward arbitrary data file list");
+                    //}
+                    requestingPeer.sendMessage(forwardArbitraryDataFileListMessage);
+                }
+            }
+        }
+    }
+
+    public void onNetworkGetArbitraryDataFileListMessage(RNSPeer peer, Message message) {
+        // Don't respond if QDN is disabled
+        if (!Settings.getInstance().isQdnEnabled()) {
+            return;
+        }
+
+        Controller.getInstance().stats.getArbitraryDataFileListMessageStats.requests.incrementAndGet();
+
+        GetArbitraryDataFileListMessage getArbitraryDataFileListMessage = (GetArbitraryDataFileListMessage) message;
+        byte[] signature = getArbitraryDataFileListMessage.getSignature();
+        String signature58 = Base58.encode(signature);
+        Long now = NTP.getTime();
+        Triple<String, RNSPeer, Long> newEntry = new Triple<>(signature58, peer, now);
+
+        // If we've seen this request recently, then ignore
+        if (arbitraryDataFileListRequests.putIfAbsent(message.getId(), newEntry) != null) {
+            LOGGER.trace("Ignoring hash list request from peer {} for signature {}", peer, signature58);
+            return;
+        }
+
+        List<byte[]> requestedHashes = getArbitraryDataFileListMessage.getHashes();
+        int hashCount = requestedHashes != null ? requestedHashes.size() : 0;
+        String requestingPeer = getArbitraryDataFileListMessage.getRequestingPeer();
+
+        if (requestingPeer != null) {
+            LOGGER.debug("Received hash list request with {} hashes from peer {} (requesting peer {}) for signature {}", hashCount, peer, requestingPeer, signature58);
+        }
+        else {
+            LOGGER.debug("Received hash list request with {} hashes from peer {} for signature {}", hashCount, peer, signature58);
+        }
+
+        List<byte[]> hashes = new ArrayList<>();
+        ArbitraryTransactionData transactionData = null;
+        boolean allChunksExist = false;
+        boolean hasMetadata = false;
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+
+            // Firstly we need to lookup this file on chain to get a list of its hashes
+            transactionData = (ArbitraryTransactionData)repository.getTransactionRepository().fromSignature(signature);
+            if (transactionData instanceof ArbitraryTransactionData) {
+
+                // Check if we're even allowed to serve data for this transaction
+                if (ArbitraryDataStorageManager.getInstance().canStoreData(transactionData)) {
+
+                    // Load file(s) and add any that exist to the list of hashes
+                    ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(transactionData);
+
+                    // If the peer didn't supply a hash list, we need to return all hashes for this transaction
+                    if (requestedHashes == null || requestedHashes.isEmpty()) {
+                        requestedHashes = new ArrayList<>();
+
+                        // Add the metadata file
+                        if (arbitraryDataFile.getMetadataHash() != null) {
+                            requestedHashes.add(arbitraryDataFile.getMetadataHash());
+                            hasMetadata = true;
+                        }
+
+                        // Add the chunk hashes
+                        if (!arbitraryDataFile.getChunkHashes().isEmpty()) {
+                            requestedHashes.addAll(arbitraryDataFile.getChunkHashes());
+                        }
+                        // Add complete file if there are no hashes
+                        else {
+                            requestedHashes.add(arbitraryDataFile.getHash());
+                        }
+                    }
+
+                    // Assume all chunks exists, unless one can't be found below
+                    allChunksExist = true;
+
+                    for (byte[] requestedHash : requestedHashes) {
+                        ArbitraryDataFileChunk chunk = ArbitraryDataFileChunk.fromHash(requestedHash, signature);
+                        if (chunk.exists()) {
+                            hashes.add(chunk.getHash());
+                            //LOGGER.trace("Added hash {}", chunk.getHash58());
+                        } else {
+                            LOGGER.trace("Couldn't add hash {} because it doesn't exist", chunk.getHash58());
+                            allChunksExist = false;
+                        }
+                    }
+                }
+            }
+
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while fetching arbitrary file list for peer %s", peer), e);
+        }
+
+        // If the only file we have is the metadata then we shouldn't respond. Most nodes will already have that,
+        // or can use the separate metadata protocol to fetch it. This should greatly reduce network spam.
+        if (hasMetadata && hashes.size() == 1) {
+            hashes.clear();
+        }
+
+        // We should only respond if we have at least one hash
+        if (!hashes.isEmpty()) {
+
+            // Firstly we should keep track of the requesting peer, to allow for potential direct connections later
+            RNSArbitraryDataFileManager.getInstance().addRecentDataRequest(requestingPeer);
+
+            // We have all the chunks, so update requests map to reflect that we've sent it
+            // There is no need to keep track of the request, as we can serve all the chunks
+            if (allChunksExist) {
+                newEntry = new Triple<>(null, null, now);
+                arbitraryDataFileListRequests.put(message.getId(), newEntry);
+            }
+
+            //String ourAddress = RNSNetwork.getInstance().getOurExternalIpAddressAndPort();
+            String ourAddress = RNSNetwork.getInstance().getBaseDestination().getHexHash();
+            ArbitraryDataFileListMessage arbitraryDataFileListMessage;
+
+            // TODO: rework for Reticulum
+            // Remove optional parameters if the requesting peer doesn't support it yet
+            // A message with less statistical data is better than no message at all
+            //if (!peer.isAtLeastVersion(MIN_PEER_VERSION_FOR_FILE_LIST_STATS)) {
+            //    arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes);
+            //} else {
+            //    arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature,
+            //            hashes, NTP.getTime(), 0, ourAddress, true);
+            //}
+            arbitraryDataFileListMessage = new ArbitraryDataFileListMessage(signature, hashes);
+
+            arbitraryDataFileListMessage.setId(message.getId());
+
+            //if (!peer.sendMessage(arbitraryDataFileListMessage)) {
+            //    LOGGER.debug("Couldn't send list of hashes");
+            //    peer.disconnect("failed to send list of hashes");
+            //    return;
+            //}
+            peer.sendMessage(arbitraryDataFileListMessage);
+            LOGGER.debug("Sent list of hashes (count: {})", hashes.size());
+
+            if (allChunksExist) {
+                // Nothing left to do, so return to prevent any unnecessary forwarding from occurring
+                LOGGER.debug("No need for any forwarding because file list request is fully served");
+                return;
+            }
+
+        }
+
+        // We may need to forward this request on
+        boolean isBlocked = (transactionData == null || ListUtils.isNameBlocked(transactionData.getName()));
+        if (Settings.getInstance().isRelayModeEnabled() && !isBlocked) {
+            // In relay mode - so ask our other peers if they have it
+
+            long requestTime = getArbitraryDataFileListMessage.getRequestTime();
+            int requestHops = getArbitraryDataFileListMessage.getRequestHops() + 1;
+            long totalRequestTime = now - requestTime;
+
+            if (totalRequestTime < RELAY_REQUEST_MAX_DURATION) {
+                // Relay request hasn't timed out yet, so can potentially be rebroadcast
+                if (requestHops < RELAY_REQUEST_MAX_HOPS) {
+                    // Relay request hasn't reached the maximum number of hops yet, so can be rebroadcast
+
+                    Message relayGetArbitraryDataFileListMessage = new GetArbitraryDataFileListMessage(signature, hashes, requestTime, requestHops, requestingPeer);
+                    relayGetArbitraryDataFileListMessage.setId(message.getId());
+
+                    LOGGER.debug("Rebroadcasting hash list request from peer {} for signature {} to our other peers... totalRequestTime: {}, requestHops: {}", peer, Base58.encode(signature), totalRequestTime, requestHops);
+                    //Network.getInstance().broadcast(
+                    //        broadcastPeer ->
+                    //                !broadcastPeer.isAtLeastVersion(RELAY_MIN_PEER_VERSION) ? null :
+                    //                broadcastPeer == peer || Objects.equals(broadcastPeer.getPeerData().getAddress().getHost(), peer.getPeerData().getAddress().getHost()) ? null : relayGetArbitraryDataFileListMessage
+                    //);
+                    RNSNetwork.getInstance().broadcast(broadcastPeer -> relayGetArbitraryDataFileListMessage);
+
+                }
+                else {
+                    // This relay request has reached the maximum number of allowed hops
+                }
+            }
+            else {
+                // This relay request has timed out
+            }
+        }
+    }
+
+}

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

@@ -0,0 +1,639 @@
+package org.qortal.controller.arbitrary;
+
+import com.google.common.net.InetAddresses;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.arbitrary.ArbitraryDataFile;
+import org.qortal.controller.Controller;
+import org.qortal.data.arbitrary.RNSArbitraryDirectConnectionInfo;
+import org.qortal.data.arbitrary.RNSArbitraryFileListResponseInfo;
+import org.qortal.data.arbitrary.RNSArbitraryRelayInfo;
+import org.qortal.data.network.PeerData;
+import org.qortal.data.transaction.ArbitraryTransactionData;
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.*;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.utils.ArbitraryTransactionUtils;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.security.SecureRandom;
+import java.util.*;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+public class RNSArbitraryDataFileManager extends Thread {
+
+    private static final Logger LOGGER = LogManager.getLogger(RNSArbitraryDataFileManager.class);
+
+    private static RNSArbitraryDataFileManager instance;
+    private volatile boolean isStopping = false;
+
+
+    /**
+     * Map to keep track of our in progress (outgoing) arbitrary data file requests
+     */
+    public Map<String, Long> arbitraryDataFileRequests = Collections.synchronizedMap(new HashMap<>());
+
+    /**
+     * Map to keep track of hashes that we might need to relay
+     */
+    public final List<RNSArbitraryRelayInfo> arbitraryRelayMap = Collections.synchronizedList(new ArrayList<>());
+
+    /**
+     * List to keep track of any arbitrary data file hash responses
+     */
+    public final List<RNSArbitraryFileListResponseInfo> arbitraryDataFileHashResponses = Collections.synchronizedList(new ArrayList<>());
+
+    /**
+     * List to keep track of peers potentially available for direct connections, based on recent requests
+     */
+    private final List<RNSArbitraryDirectConnectionInfo> directConnectionInfo = Collections.synchronizedList(new ArrayList<>());
+
+    /**
+     * Map to keep track of peers requesting QDN data that we hold.
+     * Key = peer address string, value = time of last request.
+     * This allows for additional "burst" connections beyond existing limits.
+     */
+    private Map<String, Long> recentDataRequests = Collections.synchronizedMap(new HashMap<>());
+
+
+    public static int MAX_FILE_HASH_RESPONSES = 1000;
+
+
+    private RNSArbitraryDataFileManager() {
+    }
+
+    public static RNSArbitraryDataFileManager getInstance() {
+        if (instance == null)
+            instance = new RNSArbitraryDataFileManager();
+
+        return instance;
+    }
+
+    @Override
+    public void run() {
+        Thread.currentThread().setName("Arbitrary Data File Manager");
+
+        try {
+            // Use a fixed thread pool to execute the arbitrary data file requests
+            int threadCount = 5;
+            ExecutorService arbitraryDataFileRequestExecutor = Executors.newFixedThreadPool(threadCount);
+            for (int i = 0; i < threadCount; i++) {
+                arbitraryDataFileRequestExecutor.execute(new ArbitraryDataFileRequestThread());
+            }
+
+            while (!isStopping) {
+                // Nothing to do yet
+                Thread.sleep(1000);
+            }
+        } catch (InterruptedException e) {
+            // Fall-through to exit thread...
+        }
+    }
+
+    public void shutdown() {
+        isStopping = true;
+        this.interrupt();
+    }
+
+
+    public void cleanupRequestCache(Long now) {
+        if (now == null) {
+            return;
+        }
+        final long requestMinimumTimestamp = now - ArbitraryDataManager.getInstance().ARBITRARY_REQUEST_TIMEOUT;
+        arbitraryDataFileRequests.entrySet().removeIf(entry -> entry.getValue() == null || entry.getValue() < requestMinimumTimestamp);
+
+        final long relayMinimumTimestamp = now - ArbitraryDataManager.getInstance().ARBITRARY_RELAY_TIMEOUT;
+        arbitraryRelayMap.removeIf(entry -> entry == null || entry.getTimestamp() == null || entry.getTimestamp() < relayMinimumTimestamp);
+        arbitraryDataFileHashResponses.removeIf(entry -> entry.getTimestamp() < relayMinimumTimestamp);
+
+        final long directConnectionInfoMinimumTimestamp = now - ArbitraryDataManager.getInstance().ARBITRARY_DIRECT_CONNECTION_INFO_TIMEOUT;
+        directConnectionInfo.removeIf(entry -> entry.getTimestamp() < directConnectionInfoMinimumTimestamp);
+
+        final long recentDataRequestMinimumTimestamp = now - ArbitraryDataManager.getInstance().ARBITRARY_RECENT_DATA_REQUESTS_TIMEOUT;
+        recentDataRequests.entrySet().removeIf(entry -> entry.getValue() < recentDataRequestMinimumTimestamp);
+    }
+
+
+
+    // Fetch data files by hash
+
+    public boolean fetchArbitraryDataFiles(Repository repository,
+                                           RNSPeer peer,
+                                           byte[] signature,
+                                           ArbitraryTransactionData arbitraryTransactionData,
+                                           List<byte[]> hashes) throws DataException {
+
+        // Load data file(s)
+        ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
+        boolean receivedAtLeastOneFile = false;
+
+        // Now fetch actual data from this peer
+        for (byte[] hash : hashes) {
+            if (isStopping) {
+                return false;
+            }
+            String hash58 = Base58.encode(hash);
+            if (!arbitraryDataFile.chunkExists(hash)) {
+                // Only request the file if we aren't already requesting it from someone else
+                if (!arbitraryDataFileRequests.containsKey(Base58.encode(hash))) {
+                    LOGGER.debug("Requesting data file {} from peer {}", hash58, peer);
+                    Long startTime = NTP.getTime();
+                    ArbitraryDataFile receivedArbitraryDataFile = fetchArbitraryDataFile(peer, null, arbitraryTransactionData, signature, hash, null);
+                    Long endTime = NTP.getTime();
+                    if (receivedArbitraryDataFile != null) {
+                        LOGGER.debug("Received data file {} from peer {}. Time taken: {} ms", receivedArbitraryDataFile.getHash58(), peer, (endTime-startTime));
+                        receivedAtLeastOneFile = true;
+
+                        // Remove this hash from arbitraryDataFileHashResponses now that we have received it
+                        arbitraryDataFileHashResponses.remove(hash58);
+                    }
+                    else {
+                        LOGGER.debug("Peer {} didn't respond with data file {} for signature {}. Time taken: {} ms", peer, Base58.encode(hash), Base58.encode(signature), (endTime-startTime));
+
+                        // Remove this hash from arbitraryDataFileHashResponses now that we have failed to receive it
+                        arbitraryDataFileHashResponses.remove(hash58);
+
+                        // Stop asking for files from this peer
+                        break;
+                    }
+                }
+                else {
+                    LOGGER.trace("Already requesting data file {} for signature {} from peer {}", arbitraryDataFile, Base58.encode(signature), peer);
+                }
+            }
+            else {
+                // Remove this hash from arbitraryDataFileHashResponses because we have a local copy
+                arbitraryDataFileHashResponses.remove(hash58);
+            }
+        }
+
+        if (receivedAtLeastOneFile) {
+            // Invalidate the hosted transactions cache as we are now hosting something new
+            ArbitraryDataStorageManager.getInstance().invalidateHostedTransactionsCache();
+
+            // Check if we have all the files we need for this transaction
+            if (arbitraryDataFile.allFilesExist()) {
+
+                // We have all the chunks for this transaction, so we should invalidate the transaction's name's
+                // data cache so that it is rebuilt the next time we serve it
+                ArbitraryDataManager.getInstance().invalidateCache(arbitraryTransactionData);
+            }
+        }
+
+        return receivedAtLeastOneFile;
+    }
+
+    private ArbitraryDataFile fetchArbitraryDataFile(RNSPeer peer, RNSPeer requestingPeer, ArbitraryTransactionData arbitraryTransactionData, byte[] signature, byte[] hash, Message originalMessage) throws DataException {
+        ArbitraryDataFile existingFile = ArbitraryDataFile.fromHash(hash, signature);
+        boolean fileAlreadyExists = existingFile.exists();
+        String hash58 = Base58.encode(hash);
+        ArbitraryDataFile arbitraryDataFile;
+
+        // Fetch the file if it doesn't exist locally
+        if (!fileAlreadyExists) {
+            LOGGER.debug(String.format("Fetching data file %.8s from peer %s", hash58, peer));
+            arbitraryDataFileRequests.put(hash58, NTP.getTime());
+            Message getArbitraryDataFileMessage = new GetArbitraryDataFileMessage(signature, hash);
+
+            Message response = null;
+            // TODO - revisit with RNS
+            try {
+                response = peer.getResponseWithTimeout(getArbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT);
+            } catch (InterruptedException e) {
+                // Will return below due to null response
+            }
+            arbitraryDataFileRequests.remove(hash58);
+            LOGGER.trace(String.format("Removed hash %.8s from arbitraryDataFileRequests", hash58));
+
+            // We may need to remove the file list request, if we have all the files for this transaction
+            this.handleFileListRequests(signature);
+
+            if (response == null) {
+                LOGGER.debug("Received null response from peer {}", peer);
+                return null;
+            }
+            if (response.getType() != MessageType.ARBITRARY_DATA_FILE) {
+                LOGGER.debug("Received response with invalid type: {} from peer {}", response.getType(), peer);
+                return null;
+            }
+
+            ArbitraryDataFileMessage peersArbitraryDataFileMessage = (ArbitraryDataFileMessage) response;
+            arbitraryDataFile = peersArbitraryDataFileMessage.getArbitraryDataFile();
+        } else {
+            LOGGER.debug(String.format("File hash %s already exists, so skipping the request", hash58));
+            arbitraryDataFile = existingFile;
+        }
+
+        if (arbitraryDataFile == null) {
+            // We don't have a file, so give up here
+            return null;
+        }
+
+        // We might want to forward the request to the peer that originally requested it
+        this.handleArbitraryDataFileForwarding(requestingPeer, new ArbitraryDataFileMessage(signature, arbitraryDataFile), originalMessage);
+
+        boolean isRelayRequest = (requestingPeer != null);
+        if (isRelayRequest) {
+            if (!fileAlreadyExists) {
+                // File didn't exist locally before the request, and it's a forwarding request, so delete it if it exists.
+                // It shouldn't exist on the filesystem yet, but leaving this here just in case.
+                arbitraryDataFile.delete(10);
+            }
+        }
+        else {
+            arbitraryDataFile.save();
+        }
+
+        // If this is a metadata file then we need to update the cache
+        if (arbitraryTransactionData != null && arbitraryTransactionData.getMetadataHash() != null) {
+            if (Arrays.equals(arbitraryTransactionData.getMetadataHash(), hash)) {
+                ArbitraryDataCacheManager.getInstance().addToUpdateQueue(arbitraryTransactionData);
+            }
+        }
+
+        return arbitraryDataFile;
+    }
+
+    private void handleFileListRequests(byte[] signature) {
+        try (final Repository repository = RepositoryManager.getRepository()) {
+
+            // Fetch the transaction data
+            ArbitraryTransactionData arbitraryTransactionData = ArbitraryTransactionUtils.fetchTransactionData(repository, signature);
+            if (arbitraryTransactionData == null) {
+                return;
+            }
+
+            boolean allChunksExist = ArbitraryTransactionUtils.allChunksExist(arbitraryTransactionData);
+
+            if (allChunksExist) {
+                // Update requests map to reflect that we've received all chunks
+                RNSArbitraryDataFileListManager.getInstance().deleteFileListRequestsForSignature(signature);
+            }
+
+        } catch (DataException e) {
+            LOGGER.debug("Unable to handle file list requests: {}", e.getMessage());
+        }
+    }
+
+    public void handleArbitraryDataFileForwarding(RNSPeer requestingPeer, Message message, Message originalMessage) {
+        // Return if there is no originally requesting peer to forward to
+        if (requestingPeer == null) {
+            return;
+        }
+
+        // Return if we're not in relay mode or if this request doesn't need forwarding
+        if (!Settings.getInstance().isRelayModeEnabled()) {
+            return;
+        }
+
+        LOGGER.debug("Received arbitrary data file - forwarding is needed");
+
+        // The ID needs to match that of the original request
+        message.setId(originalMessage.getId());
+
+        //if (!requestingPeer.sendMessageWithTimeout(message, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT)) {
+        //    LOGGER.debug("Failed to forward arbitrary data file to peer {}", requestingPeer);
+        //    requestingPeer.disconnect("failed to forward arbitrary data file");
+        //}
+        //else {
+        //    LOGGER.debug("Forwarded arbitrary data file to peer {}", requestingPeer);
+        //}
+        requestingPeer.sendMessageWithTimeout(message, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT);
+    }
+
+
+    // Fetch data directly from peers
+
+    private List<RNSArbitraryDirectConnectionInfo> getDirectConnectionInfoForSignature(byte[] signature) {
+        synchronized (directConnectionInfo) {
+            return directConnectionInfo.stream().filter(i -> Arrays.equals(i.getSignature(), signature)).collect(Collectors.toList());
+        }
+    }
+
+    /**
+     * Add an ArbitraryDirectConnectionInfo item, but only if one with this peer-signature combination
+     * doesn't already exist.
+     * @param connectionInfo - the direct connection info to add
+     */
+    public void addDirectConnectionInfoIfUnique(RNSArbitraryDirectConnectionInfo connectionInfo) {
+        boolean peerAlreadyExists;
+        synchronized (directConnectionInfo) {
+            peerAlreadyExists = directConnectionInfo.stream()
+                    .anyMatch(i -> Arrays.equals(i.getSignature(), connectionInfo.getSignature())
+                            && Objects.equals(i.getPeerAddress(), connectionInfo.getPeerAddress()));
+        }
+        if (!peerAlreadyExists) {
+            directConnectionInfo.add(connectionInfo);
+        }
+    }
+
+    private void removeDirectConnectionInfo(RNSArbitraryDirectConnectionInfo connectionInfo) {
+        this.directConnectionInfo.remove(connectionInfo);
+    }
+
+    public boolean fetchDataFilesFromPeersForSignature(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+
+        boolean success = false;
+
+        try {
+            while (!success) {
+                if (isStopping) {
+                    return false;
+                }
+                Thread.sleep(500L);
+
+                // Firstly fetch peers that claim to be hosting files for this signature
+                List<RNSArbitraryDirectConnectionInfo> connectionInfoList = getDirectConnectionInfoForSignature(signature);
+                if (connectionInfoList == null || connectionInfoList.isEmpty()) {
+                    LOGGER.debug("No remaining direct connection peers found for signature {}", signature58);
+                    return false;
+                }
+
+                LOGGER.debug("Attempting a direct peer connection for signature {}...", signature58);
+
+                // Peers found, so pick one with the highest number of chunks
+                Comparator<RNSArbitraryDirectConnectionInfo> highestChunkCountFirstComparator =
+                        Comparator.comparingInt(RNSArbitraryDirectConnectionInfo::getHashCount).reversed();
+                RNSArbitraryDirectConnectionInfo directConnectionInfo = connectionInfoList.stream()
+                        .sorted(highestChunkCountFirstComparator).findFirst().orElse(null);
+
+                if (directConnectionInfo == null) {
+                    return false;
+                }
+
+                // Remove from the list so that a different peer is tried next time
+                removeDirectConnectionInfo(directConnectionInfo);
+
+                //// TODO - rework this section (RNS network address?)
+                //String peerAddressString = directConnectionInfo.getPeerAddress();
+                //
+                //// Parse the peer address to find the host and port
+                //String host = null;
+                //int port = -1;
+                //String[] parts = peerAddressString.split(":");
+                //if (parts.length > 1) {
+                //    host = parts[0];
+                //    port = Integer.parseInt(parts[1]);
+                //} else {
+                //    // Assume no port included
+                //    host = peerAddressString;
+                //    // Use default listen port
+                //    port = Settings.getInstance().getDefaultListenPort();
+                //}
+                //
+                //String peerAddressStringWithPort = String.format("%s:%d", host, port);
+                //success = Network.getInstance().requestDataFromPeer(peerAddressStringWithPort, signature);
+                //
+                //int defaultPort = Settings.getInstance().getDefaultListenPort();
+                //
+                //// If unsuccessful, and using a non-standard port, try a second connection with the default listen port,
+                //// since almost all nodes use that. This is a workaround to account for any ephemeral ports that may
+                //// have made it into the dataset.
+                //if (!success) {
+                //    if (host != null && port > 0) {
+                //        if (port != defaultPort) {
+                //            String newPeerAddressString = String.format("%s:%d", host, defaultPort);
+                //            success = Network.getInstance().requestDataFromPeer(newPeerAddressString, signature);
+                //        }
+                //    }
+                //}
+                //
+                //// If _still_ unsuccessful, try matching the peer's IP address with some known peers, and then connect
+                //// to each of those in turn until one succeeds.
+                //if (!success) {
+                //    if (host != null) {
+                //        final String finalHost = host;
+                //        List<PeerData> knownPeers = Network.getInstance().getAllKnownPeers().stream()
+                //                .filter(knownPeerData -> knownPeerData.getAddress().getHost().equals(finalHost))
+                //                .collect(Collectors.toList());
+                //        // Loop through each match and attempt a connection
+                //        for (PeerData matchingPeer : knownPeers) {
+                //            String matchingPeerAddress = matchingPeer.getAddress().toString();
+                //            int matchingPeerPort = matchingPeer.getAddress().getPort();
+                //            // Make sure that it's not a port we've already tried
+                //            if (matchingPeerPort != port && matchingPeerPort != defaultPort) {
+                //                success = Network.getInstance().requestDataFromPeer(matchingPeerAddress, signature);
+                //                if (success) {
+                //                    // Successfully connected, so stop making connections
+                //                    break;
+                //                }
+                //            }
+                //        }
+                //    }
+                //}
+
+                if (success) {
+                    // We were able to connect with a peer, so track the request
+                    RNSArbitraryDataFileListManager.getInstance().addToSignatureRequests(signature58, false, true);
+                }
+
+            }
+        } catch (InterruptedException e) {
+            // Do nothing
+        }
+
+        return success;
+    }
+
+
+    // Relays
+
+    private List<RNSArbitraryRelayInfo> getRelayInfoListForHash(String hash58) {
+        synchronized (arbitraryRelayMap) {
+            return arbitraryRelayMap.stream()
+                    .filter(relayInfo -> Objects.equals(relayInfo.getHash58(), hash58))
+                    .collect(Collectors.toList());
+        }
+    }
+
+    private RNSArbitraryRelayInfo getOptimalRelayInfoEntryForHash(String hash58) {
+        LOGGER.trace("Fetching relay info for hash: {}", hash58);
+        List<RNSArbitraryRelayInfo> relayInfoList = this.getRelayInfoListForHash(hash58);
+        if (relayInfoList != null && !relayInfoList.isEmpty()) {
+
+            // Remove any with null requestHops
+            relayInfoList.removeIf(r -> r.getRequestHops() == null);
+
+            // If list is now empty, then just return one at random
+            if (relayInfoList.isEmpty()) {
+                return this.getRandomRelayInfoEntryForHash(hash58);
+            }
+
+            // Sort by number of hops (lowest first)
+            relayInfoList.sort(Comparator.comparingInt(RNSArbitraryRelayInfo::getRequestHops));
+
+            // FUTURE: secondary sort by requestTime?
+
+            RNSArbitraryRelayInfo relayInfo = relayInfoList.get(0);
+
+            LOGGER.trace("Returning optimal relay info for hash: {} (requestHops {})", hash58, relayInfo.getRequestHops());
+            return relayInfo;
+        }
+        LOGGER.trace("No relay info exists for hash: {}", hash58);
+        return null;
+    }
+
+    private RNSArbitraryRelayInfo getRandomRelayInfoEntryForHash(String hash58) {
+        LOGGER.trace("Fetching random relay info for hash: {}", hash58);
+        List<RNSArbitraryRelayInfo> relayInfoList = this.getRelayInfoListForHash(hash58);
+        if (relayInfoList != null && !relayInfoList.isEmpty()) {
+
+            // Pick random item
+            int index = new SecureRandom().nextInt(relayInfoList.size());
+            LOGGER.trace("Returning random relay info for hash: {} (index {})", hash58, index);
+            return relayInfoList.get(index);
+        }
+        LOGGER.trace("No relay info exists for hash: {}", hash58);
+        return null;
+    }
+
+    public void addToRelayMap(RNSArbitraryRelayInfo newEntry) {
+        if (newEntry == null || !newEntry.isValid()) {
+            return;
+        }
+
+        // Remove existing entry for this peer if it exists, to renew the timestamp
+        this.removeFromRelayMap(newEntry);
+
+        // Re-add
+        arbitraryRelayMap.add(newEntry);
+        LOGGER.debug("Added entry to relay map: {}", newEntry);
+    }
+
+    private void removeFromRelayMap(RNSArbitraryRelayInfo entry) {
+        arbitraryRelayMap.removeIf(relayInfo -> relayInfo.equals(entry));
+    }
+
+
+    // Peers requesting QDN data from us
+
+    /**
+     * Add an address string of a peer that is trying to request data from us.
+     * @param peerAddress
+     */
+    public void addRecentDataRequest(String peerAddress) {
+        if (peerAddress == null) {
+            return;
+        }
+
+        Long now = NTP.getTime();
+        if (now == null) {
+            return;
+        }
+
+        // Make sure to remove the port, since it isn't guaranteed to match next time
+        String[] parts = peerAddress.split(":");
+        if (parts.length == 0) {
+            return;
+        }
+        String host = parts[0];
+        if (!InetAddresses.isInetAddress(host)) {
+            // Invalid host
+            return;
+        }
+
+        this.recentDataRequests.put(host, now);
+    }
+
+    public boolean isPeerRequestingData(String peerAddressWithoutPort) {
+        return this.recentDataRequests.containsKey(peerAddressWithoutPort);
+    }
+
+    public boolean hasPendingDataRequest() {
+        return !this.recentDataRequests.isEmpty();
+    }
+
+
+    // Network handlers
+
+    public void onNetworkGetArbitraryDataFileMessage(RNSPeer peer, Message message) {
+        // Don't respond if QDN is disabled
+        if (!Settings.getInstance().isQdnEnabled()) {
+            return;
+        }
+
+        GetArbitraryDataFileMessage getArbitraryDataFileMessage = (GetArbitraryDataFileMessage) message;
+        byte[] hash = getArbitraryDataFileMessage.getHash();
+        String hash58 = Base58.encode(hash);
+        byte[] signature = getArbitraryDataFileMessage.getSignature();
+        Controller.getInstance().stats.getArbitraryDataFileMessageStats.requests.incrementAndGet();
+
+        LOGGER.debug("Received GetArbitraryDataFileMessage from peer {} for hash {}", peer, Base58.encode(hash));
+
+        try {
+            ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(hash, signature);
+            RNSArbitraryRelayInfo relayInfo = this.getOptimalRelayInfoEntryForHash(hash58);
+
+            if (arbitraryDataFile.exists()) {
+                LOGGER.trace("Hash {} exists", hash58);
+
+                // We can serve the file directly as we already have it
+                LOGGER.debug("Sending file {}...", arbitraryDataFile);
+                ArbitraryDataFileMessage arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, arbitraryDataFile);
+                arbitraryDataFileMessage.setId(message.getId());
+                //if (!peer.sendMessageWithTimeout(arbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT)) {
+                //    LOGGER.debug("Couldn't send file {}", arbitraryDataFile);
+                //    peer.disconnect("failed to send file");
+                //}
+                //else {
+                //    LOGGER.debug("Sent file {}", arbitraryDataFile);
+                //}
+                peer.sendMessageWithTimeout(arbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT);
+            }
+            //// TODO: rework (doesn't work with Reticulum)
+            //else if (relayInfo != null) {
+            //    LOGGER.debug("We have relay info for hash {}", Base58.encode(hash));
+            //    // We need to ask this peer for the file
+            //    Peer peerToAsk = relayInfo.getPeer();
+            //    if (peerToAsk != null) {
+            //
+            //        // Forward the message to this peer
+            //        LOGGER.debug("Asking peer {} for hash {}", peerToAsk, hash58);
+            //        // No need to pass arbitraryTransactionData below because this is only used for metadata caching,
+            //        // and metadata isn't retained when relaying.
+            //        this.fetchArbitraryDataFile(peerToAsk, peer, null, signature, hash, message);
+            //    }
+            //    else {
+            //        LOGGER.debug("Peer {} not found in relay info", peer);
+            //    }
+            //}
+            else {
+                LOGGER.debug("Hash {} doesn't exist and we don't have relay info", hash58);
+
+                // We don't have this file
+                Controller.getInstance().stats.getArbitraryDataFileMessageStats.unknownFiles.getAndIncrement();
+
+                // Send valid, yet unexpected message type in response, so peer's synchronizer doesn't have to wait for timeout
+                LOGGER.debug(String.format("Sending 'file unknown' response to peer %s for GET_FILE request for unknown file %s", peer, arbitraryDataFile));
+
+                //// Send generic 'unknown' message as it's very short
+                //Message fileUnknownMessage = peer.getPeersVersion() >= GenericUnknownMessage.MINIMUM_PEER_VERSION
+                //        ? new GenericUnknownMessage()
+                //        : new BlockSummariesMessage(Collections.emptyList());
+                //fileUnknownMessage.setId(message.getId());
+                //if (!peer.sendMessage(fileUnknownMessage)) {
+                //    LOGGER.debug("Couldn't sent file-unknown response");
+                //    peer.disconnect("failed to send file-unknown response");
+                //}
+                //else {
+                //    LOGGER.debug("Sent file-unknown response for file {}", arbitraryDataFile);
+                //}
+                Message fileUnknownMessage = new GenericUnknownMessage();
+                peer.sendMessage(fileUnknownMessage);
+            }
+        }
+        catch (DataException e) {
+            LOGGER.debug("Unable to handle request for arbitrary data file: {}", hash58);
+        }
+    }
+
+}

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

@@ -0,0 +1,130 @@
+package org.qortal.controller.arbitrary;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.controller.Controller;
+import org.qortal.data.arbitrary.RNSArbitraryFileListResponseInfo;
+import org.qortal.data.transaction.ArbitraryTransactionData;
+import org.qortal.event.DataMonitorEvent;
+import org.qortal.event.EventBus;
+import org.qortal.network.RNSPeer;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.ArbitraryTransactionUtils;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Iterator;
+
+import static java.lang.Thread.NORM_PRIORITY;
+
+public class RNSArbitraryDataFileRequestThread implements Runnable {
+
+    private static final Logger LOGGER = LogManager.getLogger(ArbitraryDataFileRequestThread.class);
+
+    public RNSArbitraryDataFileRequestThread() {
+
+    }
+
+    @Override
+    public void run() {
+        Thread.currentThread().setName("Arbitrary Data File Request Thread");
+        Thread.currentThread().setPriority(NORM_PRIORITY);
+
+        try {
+            while (!Controller.isStopping()) {
+                Long now = NTP.getTime();
+                this.processFileHashes(now);
+            }
+        } catch (InterruptedException e) {
+            // Fall-through to exit thread...
+        }
+    }
+
+    private void processFileHashes(Long now) throws InterruptedException {
+		if (Controller.isStopping()) {
+            return;
+        }
+
+        RNSArbitraryDataFileManager arbitraryDataFileManager = RNSArbitraryDataFileManager.getInstance();
+        String signature58 = null;
+        String hash58 = null;
+        RNSPeer peer = null;
+        boolean shouldProcess = false;
+
+        synchronized (arbitraryDataFileManager.arbitraryDataFileHashResponses) {
+            if (!arbitraryDataFileManager.arbitraryDataFileHashResponses.isEmpty()) {
+
+                // Sort by lowest number of node hops first
+                Comparator<RNSArbitraryFileListResponseInfo> lowestHopsFirstComparator =
+                        Comparator.comparingInt(RNSArbitraryFileListResponseInfo::getRequestHops);
+                arbitraryDataFileManager.arbitraryDataFileHashResponses.sort(lowestHopsFirstComparator);
+
+                Iterator iterator = arbitraryDataFileManager.arbitraryDataFileHashResponses.iterator();
+                while (iterator.hasNext()) {
+                    if (Controller.isStopping()) {
+                        return;
+                    }
+
+                    RNSArbitraryFileListResponseInfo responseInfo = (RNSArbitraryFileListResponseInfo) iterator.next();
+                    if (responseInfo == null) {
+                        iterator.remove();
+                        continue;
+                    }
+
+                    hash58 = responseInfo.getHash58();
+                    peer = responseInfo.getPeer();
+                    signature58 = responseInfo.getSignature58();
+                    Long timestamp = responseInfo.getTimestamp();
+
+                    if (now - timestamp >= ArbitraryDataManager.ARBITRARY_RELAY_TIMEOUT || signature58 == null || peer == null) {
+                        // Ignore - to be deleted
+                        iterator.remove();
+                        continue;
+                    }
+
+                    // Skip if already requesting, but don't remove, as we might want to retry later
+                    if (arbitraryDataFileManager.arbitraryDataFileRequests.containsKey(hash58)) {
+                        // Already requesting - leave this attempt for later
+                        continue;
+                    }
+
+                    // We want to process this file
+                    shouldProcess = true;
+                    iterator.remove();
+                    break;
+                }
+            }
+        }
+
+        if (!shouldProcess) {
+            // Nothing to do
+            Thread.sleep(1000L);
+            return;
+        }
+
+        byte[] hash = Base58.decode(hash58);
+        byte[] signature = Base58.decode(signature58);
+
+        // Fetch the transaction data
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            ArbitraryTransactionData arbitraryTransactionData = ArbitraryTransactionUtils.fetchTransactionData(repository, signature);
+            if (arbitraryTransactionData == null) {
+                return;
+            }
+
+            if (signature == null || hash == null || peer == null || arbitraryTransactionData == null) {
+                return;
+            }
+
+            LOGGER.trace("Fetching file {} from peer {} via request thread...", hash58, peer);
+            arbitraryDataFileManager.fetchArbitraryDataFiles(repository, peer, signature, arbitraryTransactionData, Arrays.asList(hash));
+
+        } catch (DataException e) {
+            LOGGER.debug("Unable to process file hashes: {}", e.getMessage());
+        }
+    }
+}

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

@@ -0,0 +1,481 @@
+package org.qortal.controller.arbitrary;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.arbitrary.ArbitraryDataFile;
+import org.qortal.arbitrary.ArbitraryDataResource;
+import org.qortal.arbitrary.metadata.ArbitraryDataTransactionMetadata;
+import org.qortal.controller.Controller;
+import org.qortal.data.transaction.ArbitraryTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.ArbitraryMetadataMessage;
+import org.qortal.network.message.GetArbitraryMetadataMessage;
+import org.qortal.network.message.Message;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.utils.Base58;
+import org.qortal.utils.ListUtils;
+import org.qortal.utils.NTP;
+import org.qortal.utils.Triple;
+
+import java.io.IOException;
+import java.util.*;
+
+import static org.qortal.controller.arbitrary.ArbitraryDataFileListManager.*;
+
+public class RNSArbitraryMetadataManager {
+
+    private static final Logger LOGGER = LogManager.getLogger(ArbitraryMetadataManager.class);
+
+    private static RNSArbitraryMetadataManager instance;
+
+    /**
+     * Map of recent incoming requests for ARBITRARY transaction metadata.
+     * <p>
+     * Key is original request's message ID<br>
+     * Value is Triple&lt;transaction signature in base58, first requesting peer, first request's timestamp&gt;
+     * <p>
+     * If peer is null then either:<br>
+     * <ul>
+     * <li>we are the original requesting peer</li>
+     * <li>we have already sent data payload to original requesting peer.</li>
+     * </ul>
+     * If signature is null then we have already received the file list and either:<br>
+     * <ul>
+     * <li>we are the original requesting peer and have processed it</li>
+     * <li>we have forwarded the metadata</li>
+     * </ul>
+     */
+    public Map<Integer, Triple<String, RNSPeer, Long>> arbitraryMetadataRequests = Collections.synchronizedMap(new HashMap<>());
+
+    /**
+     * Map to keep track of in progress arbitrary metadata requests
+     * Key: string - the signature encoded in base58
+     * Value: Triple<networkBroadcastCount, directPeerRequestCount, lastAttemptTimestamp>
+     */
+    private Map<String, Triple<Integer, Integer, Long>> arbitraryMetadataSignatureRequests = Collections.synchronizedMap(new HashMap<>());
+
+
+    private RNSArbitraryMetadataManager() {
+    }
+
+    public static RNSArbitraryMetadataManager getInstance() {
+        if (instance == null)
+            instance = new RNSArbitraryMetadataManager();
+
+        return instance;
+    }
+
+    public void cleanupRequestCache(Long now) {
+        if (now == null) {
+            return;
+        }
+        final long requestMinimumTimestamp = now - ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT;
+        arbitraryMetadataRequests.entrySet().removeIf(entry -> entry.getValue().getC() == null || entry.getValue().getC() < requestMinimumTimestamp);
+    }
+
+
+    public ArbitraryDataTransactionMetadata fetchMetadata(ArbitraryDataResource arbitraryDataResource, boolean useRateLimiter) {
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            // Find latest transaction
+            ArbitraryTransactionData latestTransaction = repository.getArbitraryRepository()
+                    .getLatestTransaction(arbitraryDataResource.getResourceId(), arbitraryDataResource.getService(),
+                            null, arbitraryDataResource.getIdentifier());
+
+            if (latestTransaction != null) {
+                byte[] signature = latestTransaction.getSignature();
+                byte[] metadataHash = latestTransaction.getMetadataHash();
+                if (metadataHash == null) {
+                    // This resource doesn't have metadata
+                    throw new IllegalArgumentException("This resource doesn't have metadata");
+                }
+
+                ArbitraryDataFile metadataFile = ArbitraryDataFile.fromHash(metadataHash, signature);
+                if (!metadataFile.exists()) {
+                    // Request from network
+                    this.fetchArbitraryMetadata(latestTransaction, useRateLimiter);
+                }
+
+                // Now check again as it may have been downloaded above
+                if (metadataFile.exists()) {
+                    // Use local copy
+                    ArbitraryDataTransactionMetadata transactionMetadata = new ArbitraryDataTransactionMetadata(metadataFile.getFilePath());
+                    try {
+                        transactionMetadata.read();
+                    } catch (DataException e) {
+                        // Invalid file, so delete it
+                        LOGGER.info("Deleting invalid metadata file due to exception: {}", e.getMessage());
+                        transactionMetadata.delete();
+                        return null;
+                    }
+                    return transactionMetadata;
+                }
+            }
+
+        } catch (DataException | IOException e) {
+            LOGGER.error("Repository issue when fetching arbitrary transaction metadata", e);
+        }
+
+        return null;
+    }
+
+
+    // Request metadata from network
+
+    public byte[] fetchArbitraryMetadata(ArbitraryTransactionData arbitraryTransactionData, boolean useRateLimiter) {
+        byte[] metadataHash = arbitraryTransactionData.getMetadataHash();
+        if (metadataHash == null) {
+            return null;
+        }
+
+        byte[] signature = arbitraryTransactionData.getSignature();
+        String signature58 = Base58.encode(signature);
+
+        // Require an NTP sync
+        Long now = NTP.getTime();
+        if (now == null) {
+            return null;
+        }
+
+        // If we've already tried too many times in a short space of time, make sure to give up
+        if (useRateLimiter && !this.shouldMakeMetadataRequestForSignature(signature58)) {
+            LOGGER.trace("Skipping metadata request for signature {} due to rate limit", signature58);
+            return null;
+        }
+        this.addToSignatureRequests(signature58, true, false);
+
+        //List<Peer> handshakedPeers = Network.getInstance().getImmutableHandshakedPeers();
+        List<RNSPeer> handshakedPeers = RNSNetwork.getInstance().getLinkedPeers();
+        LOGGER.debug(String.format("Sending metadata request for signature %s to %d peers...", signature58, handshakedPeers.size()));
+
+        // Build request
+        Message getArbitraryMetadataMessage = new GetArbitraryMetadataMessage(signature, now, 0);
+
+        // Save our request into requests map
+        Triple<String, RNSPeer, Long> requestEntry = new Triple<>(signature58, null, NTP.getTime());
+
+        // Assign random ID to this message
+        int id;
+        do {
+            id = new Random().nextInt(Integer.MAX_VALUE - 1) + 1;
+
+            // Put queue into map (keyed by message ID) so we can poll for a response
+            // If putIfAbsent() doesn't return null, then this ID is already taken
+        } while (arbitraryMetadataRequests.put(id, requestEntry) != null);
+        getArbitraryMetadataMessage.setId(id);
+
+        // Broadcast request
+        RNSNetwork.getInstance().broadcast(peer -> getArbitraryMetadataMessage);
+
+        // Poll to see if data has arrived
+        final long singleWait = 100;
+        long totalWait = 0;
+        while (totalWait < ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT) {
+            try {
+                Thread.sleep(singleWait);
+            } catch (InterruptedException e) {
+                break;
+            }
+
+            requestEntry = arbitraryMetadataRequests.get(id);
+            if (requestEntry == null)
+                return null;
+
+            if (requestEntry.getA() == null)
+                break;
+
+            totalWait += singleWait;
+        }
+
+        try {
+            ArbitraryDataFile metadataFile = ArbitraryDataFile.fromHash(metadataHash, signature);
+            if (metadataFile.exists()) {
+                return metadataFile.getBytes();
+            }
+        } catch (DataException e) {
+            // Do nothing
+        }
+
+        return null;
+    }
+
+
+    // Track metadata lookups by signature
+
+    private boolean shouldMakeMetadataRequestForSignature(String signature58) {
+        Triple<Integer, Integer, Long> request = arbitraryMetadataSignatureRequests.get(signature58);
+
+        if (request == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        // Extract the components
+        Integer networkBroadcastCount = request.getA();
+        // Integer directPeerRequestCount = request.getB();
+        Long lastAttemptTimestamp = request.getC();
+
+        if (lastAttemptTimestamp == null) {
+            // Not attempted yet
+            return true;
+        }
+
+        long timeSinceLastAttempt = NTP.getTime() - lastAttemptTimestamp;
+
+        // Allow a second attempt after 60 seconds
+        if (timeSinceLastAttempt > 60 * 1000L) {
+            // We haven't tried for at least 60 seconds
+
+            if (networkBroadcastCount < 2) {
+                // We've made less than 2 total attempts
+                return true;
+            }
+        }
+
+        // Then allow another attempt after 60 minutes
+        if (timeSinceLastAttempt > 60 * 60 * 1000L) {
+            // We haven't tried for at least 60 minutes
+
+            if (networkBroadcastCount < 3) {
+                // We've made less than 3 total attempts
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public boolean isSignatureRateLimited(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+        return !this.shouldMakeMetadataRequestForSignature(signature58);
+    }
+
+    public long lastRequestForSignature(byte[] signature) {
+        String signature58 = Base58.encode(signature);
+        Triple<Integer, Integer, Long> request = arbitraryMetadataSignatureRequests.get(signature58);
+
+        if (request == null) {
+            // Not attempted yet
+            return 0;
+        }
+
+        // Extract the components
+        Long lastAttemptTimestamp = request.getC();
+        if (lastAttemptTimestamp != null) {
+            return  lastAttemptTimestamp;
+        }
+        return 0;
+    }
+
+    public void addToSignatureRequests(String signature58, boolean incrementNetworkRequests, boolean incrementPeerRequests) {
+        Triple<Integer, Integer, Long> request  = arbitraryMetadataSignatureRequests.get(signature58);
+        Long now = NTP.getTime();
+
+        if (request == null) {
+            // No entry yet
+            Triple<Integer, Integer, Long> newRequest = new Triple<>(0, 0, now);
+            arbitraryMetadataSignatureRequests.put(signature58, newRequest);
+        }
+        else {
+            // There is an existing entry
+            if (incrementNetworkRequests) {
+                request.setA(request.getA() + 1);
+            }
+            if (incrementPeerRequests) {
+                request.setB(request.getB() + 1);
+            }
+            request.setC(now);
+            arbitraryMetadataSignatureRequests.put(signature58, request);
+        }
+    }
+
+    public void removeFromSignatureRequests(String signature58) {
+        arbitraryMetadataSignatureRequests.remove(signature58);
+    }
+
+
+    // Network handlers
+
+    public void onNetworkArbitraryMetadataMessage(RNSPeer peer, Message message) {
+        // Don't process if QDN is disabled
+        if (!Settings.getInstance().isQdnEnabled()) {
+            return;
+        }
+
+        ArbitraryMetadataMessage arbitraryMetadataMessage = (ArbitraryMetadataMessage) message;
+        LOGGER.debug("Received metadata from peer {}", peer);
+
+        // Do we have a pending request for this data?
+        Triple<String, RNSPeer, Long> request = arbitraryMetadataRequests.get(message.getId());
+        if (request == null || request.getA() == null) {
+            return;
+        }
+        boolean isRelayRequest = (request.getB() != null);
+
+        // Does this message's signature match what we're expecting?
+        byte[] signature = arbitraryMetadataMessage.getSignature();
+        String signature58 = Base58.encode(signature);
+        if (!request.getA().equals(signature58)) {
+            return;
+        }
+
+        // Update requests map to reflect that we've received this metadata
+        Triple<String, RNSPeer, Long> newEntry = new Triple<>(null, null, request.getC());
+        arbitraryMetadataRequests.put(message.getId(), newEntry);
+
+        // Get transaction info
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            TransactionData transactionData = repository.getTransactionRepository().fromSignature(signature);
+            if (!(transactionData instanceof ArbitraryTransactionData)) {
+                return;
+            }
+            ArbitraryTransactionData arbitraryTransactionData = (ArbitraryTransactionData) transactionData;
+
+            // Check if the name is blocked
+            boolean isBlocked = (arbitraryTransactionData == null || ListUtils.isNameBlocked(arbitraryTransactionData.getName()));
+
+            // Save if not blocked
+            ArbitraryDataFile arbitraryMetadataFile = arbitraryMetadataMessage.getArbitraryMetadataFile();
+            if (!isBlocked && arbitraryMetadataFile != null) {
+                arbitraryMetadataFile.save();
+            }
+
+            // Forwarding
+            if (isRelayRequest && Settings.getInstance().isRelayModeEnabled()) {
+                if (!isBlocked) {
+                    RNSPeer requestingPeer = request.getB();
+                    if (requestingPeer != null) {
+
+                        ArbitraryMetadataMessage forwardArbitraryMetadataMessage = new ArbitraryMetadataMessage(signature, arbitraryMetadataMessage.getArbitraryMetadataFile());
+                        forwardArbitraryMetadataMessage.setId(arbitraryMetadataMessage.getId());
+
+                        // Forward to requesting peer
+                        LOGGER.debug("Forwarding metadata to requesting peer: {}", requestingPeer);
+                        //if (!requestingPeer.sendMessage(forwardArbitraryMetadataMessage)) {
+                        //    requestingPeer.disconnect("failed to forward arbitrary metadata");
+                        //}
+                        requestingPeer.sendMessage(forwardArbitraryMetadataMessage);
+                    }
+                }
+            }
+
+            // Add to resource queue to update arbitrary resource caches
+            if (arbitraryTransactionData != null) {
+                ArbitraryDataCacheManager.getInstance().addToUpdateQueue(arbitraryTransactionData);
+            }
+
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while saving arbitrary transaction metadata from peer %s", peer), e);
+        }
+    }
+
+    public void onNetworkGetArbitraryMetadataMessage(RNSPeer peer, Message message) {
+        // Don't respond if QDN is disabled
+        if (!Settings.getInstance().isQdnEnabled()) {
+            return;
+        }
+
+        Controller.getInstance().stats.getArbitraryMetadataMessageStats.requests.incrementAndGet();
+
+        GetArbitraryMetadataMessage getArbitraryMetadataMessage = (GetArbitraryMetadataMessage) message;
+        byte[] signature = getArbitraryMetadataMessage.getSignature();
+        String signature58 = Base58.encode(signature);
+        Long now = NTP.getTime();
+        Triple<String, RNSPeer, Long> newEntry = new Triple<>(signature58, peer, now);
+
+        // If we've seen this request recently, then ignore
+        if (arbitraryMetadataRequests.putIfAbsent(message.getId(), newEntry) != null) {
+            LOGGER.debug("Ignoring metadata request from peer {} for signature {}", peer, signature58);
+            return;
+        }
+
+        LOGGER.debug("Received metadata request from peer {} for signature {}", peer, signature58);
+
+        ArbitraryTransactionData transactionData = null;
+        ArbitraryDataFile metadataFile = null;
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+
+            // Firstly we need to lookup this file on chain to get its metadata hash
+            transactionData = (ArbitraryTransactionData)repository.getTransactionRepository().fromSignature(signature);
+            if (transactionData instanceof ArbitraryTransactionData) {
+
+                // Check if we're even allowed to serve metadata for this transaction
+                if (ArbitraryDataStorageManager.getInstance().canStoreData(transactionData)) {
+
+                    byte[] metadataHash = transactionData.getMetadataHash();
+                    if (metadataHash != null) {
+
+                        // Load metadata file
+                        metadataFile = ArbitraryDataFile.fromHash(metadataHash, signature);
+                    }
+                }
+            }
+
+        } catch (DataException e) {
+            LOGGER.error(String.format("Repository issue while fetching arbitrary metadata for peer %s", peer), e);
+        }
+
+        // We should only respond if we have the metadata file
+        if (metadataFile != null && metadataFile.exists()) {
+
+            // We have the metadata file, so update requests map to reflect that we've sent it
+            newEntry = new Triple<>(null, null, now);
+            arbitraryMetadataRequests.put(message.getId(), newEntry);
+
+            ArbitraryMetadataMessage arbitraryMetadataMessage = new ArbitraryMetadataMessage(signature, metadataFile);
+            arbitraryMetadataMessage.setId(message.getId());
+            //if (!peer.sendMessage(arbitraryMetadataMessage)) {
+            //    LOGGER.debug("Couldn't send metadata");
+            //    peer.disconnect("failed to send metadata");
+            //    return;
+            //}
+            peer.sendMessage(arbitraryMetadataMessage);
+            LOGGER.debug("Sent metadata");
+
+            // Nothing left to do, so return to prevent any unnecessary forwarding from occurring
+            LOGGER.debug("No need for any forwarding because metadata request is fully served");
+            return;
+
+        }
+
+        // We may need to forward this request on
+        boolean isBlocked = (transactionData == null || ListUtils.isNameBlocked(transactionData.getName()));
+        if (Settings.getInstance().isRelayModeEnabled() && !isBlocked) {
+            // In relay mode - so ask our other peers if they have it
+
+            long requestTime = getArbitraryMetadataMessage.getRequestTime();
+            int requestHops = getArbitraryMetadataMessage.getRequestHops() + 1;
+            long totalRequestTime = now - requestTime;
+
+            if (totalRequestTime < RELAY_REQUEST_MAX_DURATION) {
+                // Relay request hasn't timed out yet, so can potentially be rebroadcast
+                if (requestHops < RELAY_REQUEST_MAX_HOPS) {
+                    // Relay request hasn't reached the maximum number of hops yet, so can be rebroadcast
+
+                    Message relayGetArbitraryMetadataMessage = new GetArbitraryMetadataMessage(signature, requestTime, requestHops);
+                    relayGetArbitraryMetadataMessage.setId(message.getId());
+
+                    LOGGER.debug("Rebroadcasting metadata request from peer {} for signature {} to our other peers... totalRequestTime: {}, requestHops: {}", peer, Base58.encode(signature), totalRequestTime, requestHops);
+                    //Network.getInstance().broadcast(
+                    //        broadcastPeer ->
+                    //                !broadcastPeer.isAtLeastVersion(RELAY_MIN_PEER_VERSION) ? null :
+                    //                broadcastPeer == peer || Objects.equals(broadcastPeer.getPeerData().getAddress().getHost(), peer.getPeerData().getAddress().getHost()) ? null : relayGetArbitraryMetadataMessage);
+                    RNSNetwork.getInstance().broadcast(broadcastPeer -> relayGetArbitraryMetadataMessage);
+
+                }
+                else {
+                    // This relay request has reached the maximum number of allowed hops
+                }
+            }
+            else {
+                // This relay request has timed out
+            }
+        }
+    }
+
+}

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

@@ -0,0 +1,778 @@
+package org.qortal.controller.tradebot;
+
+import com.google.common.primitives.Longs;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.ECKey;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.controller.Controller;
+import org.qortal.controller.Synchronizer;
+import org.qortal.controller.tradebot.AcctTradeBot.ResponseResult;
+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.network.TradePresenceData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.gui.SysTray;
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.GetTradePresencesMessage;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.TradePresencesMessage;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBImportExport;
+import org.qortal.settings.Settings;
+import org.qortal.transaction.Transaction;
+import org.qortal.utils.ByteArray;
+import org.qortal.utils.NTP;
+
+import java.awt.TrayIcon.MessageType;
+import java.security.SecureRandom;
+import java.util.*;
+import java.util.function.Supplier;
+
+/**
+ * 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 RNSTradeBot implements Listener {
+
+	private static final Logger LOGGER = LogManager.getLogger(TradeBot.class);
+	private static final Random RANDOM = new SecureRandom();
+
+	/** Maximum lifetime of trade presence timestamp. 30 mins in ms. */
+	private static final long PRESENCE_LIFETIME = 30 * 60 * 1000L;
+	/** How soon before expiry of our own trade presence timestamp that we want to trigger renewal. 5 mins in ms. */
+	private static final long EARLY_RENEWAL_PERIOD = 5 * 60 * 1000L;
+	/** Trade presence timestamps are rounded up to this nearest interval. Bigger values improve grouping of entries in [GET_]TRADE_PRESENCES network messages. 15 mins in ms. */
+	private static final long EXPIRY_ROUNDING = 15 * 60 * 1000L;
+	/** How often we want to broadcast our list of all known trade presences to peers. 5 mins in ms. */
+	private static final long PRESENCE_BROADCAST_INTERVAL = 5 * 60 * 1000L;
+
+	public interface StateNameAndValueSupplier {
+		public String getState();
+		public int getStateValue();
+	}
+
+	public static class StateChangeEvent implements Event {
+		private final TradeBotData tradeBotData;
+
+		public StateChangeEvent(TradeBotData tradeBotData) {
+			this.tradeBotData = tradeBotData;
+		}
+
+		public TradeBotData getTradeBotData() {
+			return this.tradeBotData;
+		}
+	}
+
+	public static class TradePresenceEvent implements Event {
+		private final TradePresenceData tradePresenceData;
+
+		public TradePresenceEvent(TradePresenceData tradePresenceData) {
+			this.tradePresenceData = tradePresenceData;
+		}
+
+		public TradePresenceData getTradePresenceData() {
+			return this.tradePresenceData;
+		}
+	}
+
+	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(LitecoinACCTv3.class, LitecoinACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(DogecoinACCTv1.class, DogecoinACCTv1TradeBot::getInstance);
+		acctTradeBotSuppliers.put(DogecoinACCTv3.class, DogecoinACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(DigibyteACCTv3.class, DigibyteACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(RavencoinACCTv3.class, RavencoinACCTv3TradeBot::getInstance);
+		acctTradeBotSuppliers.put(PirateChainACCTv3.class, PirateChainACCTv3TradeBot::getInstance);
+	}
+
+	private static RNSTradeBot instance;
+
+	private final Map<ByteArray, Long> ourTradePresenceTimestampsByPubkey = Collections.synchronizedMap(new HashMap<>());
+	private final List<TradePresenceData> pendingTradePresences = Collections.synchronizedList(new ArrayList<>());
+
+	private final Map<ByteArray, TradePresenceData> allTradePresencesByPubkey = Collections.synchronizedMap(new HashMap<>());
+	private Map<ByteArray, TradePresenceData> safeAllTradePresencesByPubkey = Collections.emptyMap();
+	private long nextTradePresenceBroadcastTimestamp = 0L;
+
+	private Map<String, Long> failedTrades = new HashMap<>();
+	private Map<String, Long> validTrades = new HashMap<>();
+
+	private RNSTradeBot() {
+		EventBus.INSTANCE.addListener(event -> RNSTradeBot.getInstance().listen(event));
+	}
+
+	public static synchronized RNSTradeBot getInstance() {
+		if (instance == null)
+			instance = new RNSTradeBot();
+
+		return instance;
+	}
+
+	public ACCT getAcctUsingAtData(ATData atData) {
+		byte[] codeHash = atData.getCodeHash();
+		if (codeHash == null)
+			return null;
+
+		return SupportedBlockchain.getAcctByCodeHash(codeHash);
+	}
+
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+		ACCT acct = this.getAcctUsingAtData(atData);
+		if (acct == null)
+			return null;
+
+		return acct.populateTradeData(repository, atData);
+	}
+
+	/**
+	 * Creates a new trade-bot entry from the "Bob" viewpoint,
+	 * i.e. OFFERing QORT in exchange for foreign blockchain currency.
+	 * <p>
+	 * Generates:
+	 * <ul>
+	 * 	<li>new 'trade' private key</li>
+	 * 	<li>secret(s)</li>
+	 * </ul>
+	 * Derives:
+	 * <ul>
+	 * 	<li>'native' (as in Qortal) public key, public key hash, address (starting with Q)</li>
+	 * 	<li>'foreign' public key, public key hash</li>
+	 *	<li>hash(es) of secret(s)</li>
+	 * </ul>
+	 * A Qortal AT is then constructed including the following as constants in the 'data segment':
+	 * <ul>
+	 * 	<li>'native' (Qortal) 'trade' address - used to MESSAGE AT</li>
+	 * 	<li>'foreign' public key hash - used by Alice's to allow redeem of currency on foreign blockchain</li>
+	 * 	<li>hash(es) of secret(s) - used by AT (optional) and foreign blockchain as needed</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>foreign currency 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 {
+		// Fetch latest ACCT version for requested foreign blockchain
+		ACCT acct = tradeBotCreateRequest.foreignBlockchain.getLatestAcct();
+
+		AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+		if (acctTradeBot == null)
+			return null;
+
+		return acctTradeBot.createTrade(repository, tradeBotCreateRequest);
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint,
+	 * i.e. matching foreign blockchain currency to an existing QORT offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a foreign blockchain wallet via <tt>foreignKey</tt>.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeData chosen trade OFFER that Alice wants to match
+	 * @param foreignKey foreign blockchain wallet key
+	 * @throws DataException
+	 */
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct,
+			CrossChainTradeData crossChainTradeData, String foreignKey, String receivingAddress) throws DataException {
+		AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+		if (acctTradeBot == null) {
+			LOGGER.debug(() -> String.format("Couldn't find ACCT trade-bot for AT %s", atData.getATAddress()));
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Check Alice doesn't already have an existing, on-going trade-bot entry for this AT.
+		if (repository.getCrossChainRepository().existsTradeWithAtExcludingStates(atData.getATAddress(), acctTradeBot.getEndStates()))
+			return ResponseResult.TRADE_ALREADY_EXISTS;
+
+		return acctTradeBot.startResponse(repository, atData, acct, crossChainTradeData, foreignKey, receivingAddress);
+	}
+
+	/**
+	 * Creates a trade-bot entries from the 'Alice' viewpoint,
+	 * i.e. matching foreign blockchain currency to existing QORT offers.
+	 * <p>
+	 * Requires chosen trade offers from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a foreign blockchain wallet via <tt>foreignKey</tt>.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeDataList chosen trade OFFERs that Alice wants to match
+	 * @param receiveAddress Alice's Qortal address to receive her QORT
+	 * @param foreignKey foreign blockchain wallet key
+	 * @param bitcoiny
+	 * @throws DataException
+	 */
+	public ResponseResult startResponseMultiple(
+			Repository repository,
+			ACCT acct,
+			List<CrossChainTradeData> crossChainTradeDataList,
+			String receiveAddress,
+			String foreignKey,
+			Bitcoiny bitcoiny) throws DataException {
+		AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+		if (acctTradeBot == null) {
+			LOGGER.debug(() -> String.format("Couldn't find ACCT trade-bot for %s", acct.getBlockchain()));
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		for( CrossChainTradeData tradeData : crossChainTradeDataList) {
+			// Check Alice doesn't already have an existing, on-going trade-bot entry for this AT.
+			if (repository.getCrossChainRepository().existsTradeWithAtExcludingStates(tradeData.qortalAtAddress, acctTradeBot.getEndStates()))
+				return ResponseResult.TRADE_ALREADY_EXISTS;
+		}
+		return TradeBotUtils.startResponseMultiple(repository, acct, crossChainTradeDataList, receiveAddress, foreignKey, bitcoiny);
+	}
+
+	public boolean deleteEntry(Repository repository, byte[] tradePrivateKey) throws DataException {
+		TradeBotData tradeBotData = repository.getCrossChainRepository().getTradeBotData(tradePrivateKey);
+		if (tradeBotData == null)
+			// Can't delete what we don't have!
+			return false;
+
+		boolean canDelete = false;
+
+		ACCT acct = SupportedBlockchain.getAcctByName(tradeBotData.getAcctName());
+		if (acct == null)
+			// We can't/no longer support this ACCT
+			canDelete = true;
+		else {
+			AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+			canDelete = acctTradeBot == null || acctTradeBot.canDelete(repository, tradeBotData);
+		}
+
+		if (canDelete) {
+			repository.getCrossChainRepository().delete(tradePrivateKey);
+			repository.saveChanges();
+		}
+
+		return canDelete;
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Synchronizer.NewChainTipEvent))
+			return;
+
+		// Don't process trade bots or broadcast presence timestamps if our chain is more than 60 minutes old
+		final Long minLatestBlockTimestamp = NTP.getTime() - (60 * 60 * 1000L);
+		if (!Controller.getInstance().isUpToDate(minLatestBlockTimestamp))
+			return;
+
+		synchronized (this) {
+			expireOldPresenceTimestamps();
+
+			List<TradeBotData> allTradeBotData;
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
+			} catch (DataException e) {
+				LOGGER.error("Couldn't run trade bot due to repository issue", e);
+				return;
+			}
+
+			for (TradeBotData tradeBotData : allTradeBotData)
+				try (final Repository repository = RepositoryManager.getRepository()) {
+					// Find ACCT-specific trade-bot for this entry
+					ACCT acct = SupportedBlockchain.getAcctByName(tradeBotData.getAcctName());
+					if (acct == null) {
+						LOGGER.debug(() -> String.format("Couldn't find ACCT matching name %s", tradeBotData.getAcctName()));
+						continue;
+					}
+
+					AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+					if (acctTradeBot == null) {
+						LOGGER.debug(() -> String.format("Couldn't find ACCT trade-bot matching name %s", tradeBotData.getAcctName()));
+						continue;
+					}
+
+					acctTradeBot.progress(repository, tradeBotData);
+				} catch (DataException e) {
+					LOGGER.error("Couldn't run trade bot due to repository issue", e);
+				} catch (ForeignBlockchainException e) {
+					LOGGER.warn(() -> String.format("Foreign blockchain issue processing trade-bot entry for AT %s: %s", tradeBotData.getAtAddress(), e.getMessage()));
+				}
+
+			broadcastPresenceTimestamps();
+		}
+	}
+
+	public static byte[] generateTradePrivateKey() {
+		// The private key is used for both Curve25519 and secp256k1 so needs to be valid for both.
+		// Curve25519 accepts any seed, so generate a valid secp256k1 key and use that.
+		return new ECKey().getPrivKeyBytes();
+	}
+
+	public static byte[] deriveTradeNativePublicKey(byte[] privateKey) {
+		return Crypto.toPublicKey(privateKey);
+	}
+
+	public static byte[] deriveTradeForeignPublicKey(byte[] privateKey) {
+		return ECKey.fromPrivate(privateKey).getPubKey();
+	}
+
+	/*package*/ public static byte[] generateSecret() {
+		byte[] secret = new byte[32];
+		RANDOM.nextBytes(secret);
+		return secret;
+	}
+
+	/*package*/ static void backupTradeBotData(Repository repository, List<TradeBotData> additional) {
+		// Attempt to backup the trade bot data. This an optional step and doesn't impact trading, so don't throw an exception on failure
+		try {
+			LOGGER.info("About to backup trade bot data...");
+			HSQLDBImportExport.backupTradeBotStates(repository, additional);
+		} catch (DataException e) {
+			LOGGER.info(String.format("Repository issue when exporting trade bot data: %s", e.getMessage()));
+		}
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData,
+			String newState, int newStateValue, Supplier<String> logMessageSupplier) throws DataException {
+		tradeBotData.setState(newState);
+		tradeBotData.setStateValue(newStateValue);
+		tradeBotData.setTimestamp(NTP.getTime());
+		repository.getCrossChainRepository().save(tradeBotData);
+		repository.saveChanges();
+
+		if (Settings.getInstance().isTradebotSystrayEnabled())
+			SysTray.getInstance().showMessage("Trade-Bot", String.format("%s: %s", tradeBotData.getAtAddress(), newState), MessageType.INFO);
+
+		if (logMessageSupplier != null)
+			LOGGER.info(logMessageSupplier.get());
+
+		LOGGER.debug(() -> String.format("new state for trade-bot entry based on AT %s: %s", tradeBotData.getAtAddress(), newState));
+
+		notifyStateChange(tradeBotData);
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData, StateNameAndValueSupplier newStateSupplier, Supplier<String> logMessageSupplier) throws DataException {
+		updateTradeBotState(repository, tradeBotData, newStateSupplier.getState(), newStateSupplier.getStateValue(), logMessageSupplier);
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData, Supplier<String> logMessageSupplier) throws DataException {
+		updateTradeBotState(repository, tradeBotData, tradeBotData.getState(), tradeBotData.getStateValue(), logMessageSupplier);
+	}
+
+	/*package*/ static void notifyStateChange(TradeBotData tradeBotData) {
+		StateChangeEvent stateChangeEvent = new StateChangeEvent(tradeBotData);
+		EventBus.INSTANCE.notify(stateChangeEvent);
+	}
+
+	/*package*/ static AcctTradeBot findTradeBotForAcct(ACCT acct) {
+		Supplier<AcctTradeBot> acctTradeBotSupplier = acctTradeBotSuppliers.get(acct.getClass());
+		if (acctTradeBotSupplier == null)
+			return null;
+
+		return acctTradeBotSupplier.get();
+	}
+
+	// PRESENCE-related
+
+	public Collection<TradePresenceData> getAllTradePresences() {
+		return this.safeAllTradePresencesByPubkey.values();
+	}
+
+	/** Trade presence timestamps expire in the 'future' so any that reach 'now' have expired and are removed. */
+	private void expireOldPresenceTimestamps() {
+		long now = NTP.getTime();
+
+		int allRemovedCount = 0;
+		synchronized (this.allTradePresencesByPubkey) {
+			int preRemoveCount = this.allTradePresencesByPubkey.size();
+			this.allTradePresencesByPubkey.values().removeIf(tradePresenceData -> tradePresenceData.getTimestamp() <= now);
+			allRemovedCount = this.allTradePresencesByPubkey.size() - preRemoveCount;
+		}
+
+		int ourRemovedCount = 0;
+		synchronized (this.ourTradePresenceTimestampsByPubkey) {
+			int preRemoveCount = this.ourTradePresenceTimestampsByPubkey.size();
+			this.ourTradePresenceTimestampsByPubkey.values().removeIf(timestamp -> timestamp < now);
+			ourRemovedCount = this.ourTradePresenceTimestampsByPubkey.size() - preRemoveCount;
+		}
+
+		if (allRemovedCount > 0)
+			LOGGER.debug("Removed {} expired trade presences, of which {} ours", allRemovedCount, ourRemovedCount);
+	}
+
+	/*package*/ void updatePresence(Repository repository, TradeBotData tradeBotData, CrossChainTradeData tradeData)
+			throws DataException {
+		String atAddress = tradeBotData.getAtAddress();
+
+		PrivateKeyAccount tradeNativeAccount = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+		String signerAddress = tradeNativeAccount.getAddress();
+
+		/*
+		* There's no point in Alice trying to broadcast presence for an AT that isn't locked to her,
+		* as other peers won't be able to verify as signing public key isn't yet in the AT's data segment.
+		*/
+		if (!signerAddress.equals(tradeData.qortalCreatorTradeAddress) && !signerAddress.equals(tradeData.qortalPartnerAddress)) {
+			// Signer is neither Bob, nor trade locked to Alice
+			LOGGER.trace("Can't provide trade presence for our AT {} as it's not yet locked to Alice", atAddress);
+			return;
+		}
+
+		long now = NTP.getTime();
+		long newExpiry = generateExpiry(now);
+		ByteArray pubkeyByteArray = ByteArray.wrap(tradeNativeAccount.getPublicKey());
+
+		// If map entry's timestamp is missing, or within early renewal period, use the new expiry - otherwise use existing timestamp.
+		synchronized (this.ourTradePresenceTimestampsByPubkey) {
+			Long currentTimestamp = this.ourTradePresenceTimestampsByPubkey.get(pubkeyByteArray);
+
+			if (currentTimestamp != null && currentTimestamp - now > EARLY_RENEWAL_PERIOD) {
+				// timestamp still good
+				LOGGER.trace("Current trade presence timestamp {} still good for our trade {}", currentTimestamp, atAddress);
+				return;
+			}
+
+			this.ourTradePresenceTimestampsByPubkey.put(pubkeyByteArray, newExpiry);
+		}
+
+		// Create signature
+		byte[] signature = tradeNativeAccount.sign(Longs.toByteArray(newExpiry));
+
+		// Add new trade presence to queue to be broadcast around network
+		TradePresenceData tradePresenceData = new TradePresenceData(newExpiry, tradeNativeAccount.getPublicKey(), signature, atAddress);
+		this.pendingTradePresences.add(tradePresenceData);
+
+		this.allTradePresencesByPubkey.put(pubkeyByteArray, tradePresenceData);
+		rebuildSafeAllTradePresences();
+
+		LOGGER.trace("New trade presence timestamp {} for our trade {}", newExpiry, atAddress);
+
+		EventBus.INSTANCE.notify(new TradePresenceEvent(tradePresenceData));
+	}
+
+	private void rebuildSafeAllTradePresences() {
+		synchronized (this.allTradePresencesByPubkey) {
+			// Collect into a *new* unmodifiable map.
+			this.safeAllTradePresencesByPubkey = Map.copyOf(this.allTradePresencesByPubkey);
+		}
+	}
+
+	private void broadcastPresenceTimestamps() {
+		// If we have new trade presences that are pending broadcast, send those as a priority
+		if (!this.pendingTradePresences.isEmpty()) {
+			// Create a copy for Network to safely use in another thread
+			List<TradePresenceData> safeTradePresences;
+			synchronized (this.pendingTradePresences) {
+				safeTradePresences = List.copyOf(this.pendingTradePresences);
+				this.pendingTradePresences.clear();
+			}
+
+			LOGGER.debug("Broadcasting {} new trade presences", safeTradePresences.size());
+
+			TradePresencesMessage tradePresencesMessage = new TradePresencesMessage(safeTradePresences);
+			RNSNetwork.getInstance().broadcast(peer -> tradePresencesMessage);
+
+			return;
+		}
+
+		// As we have no new trade presences, check whether it's time to do a general broadcast
+		Long now = NTP.getTime();
+		if (now == null || now < nextTradePresenceBroadcastTimestamp)
+			return;
+
+		nextTradePresenceBroadcastTimestamp = now + PRESENCE_BROADCAST_INTERVAL;
+
+		List<TradePresenceData> safeTradePresences = List.copyOf(this.safeAllTradePresencesByPubkey.values());
+
+		LOGGER.debug("Broadcasting all {} known trade presences. Next broadcast timestamp: {}",
+				safeTradePresences.size(), nextTradePresenceBroadcastTimestamp
+		);
+
+		GetTradePresencesMessage getTradePresencesMessage = new GetTradePresencesMessage(safeTradePresences);
+		RNSNetwork.getInstance().broadcast(peer -> getTradePresencesMessage);
+	}
+
+	// Network message processing
+
+	public void onGetTradePresencesMessage(RNSPeer peer, Message message) {
+		GetTradePresencesMessage getTradePresencesMessage = (GetTradePresencesMessage) message;
+
+		List<TradePresenceData> peersTradePresences = getTradePresencesMessage.getTradePresences();
+
+		// Create mutable copy from safe snapshot
+		Map<ByteArray, TradePresenceData> entriesUnknownToPeer = new HashMap<>(this.safeAllTradePresencesByPubkey);
+		int knownCount = entriesUnknownToPeer.size();
+
+		for (TradePresenceData peersTradePresence : peersTradePresences) {
+			ByteArray pubkeyByteArray = ByteArray.wrap(peersTradePresence.getPublicKey());
+
+			TradePresenceData ourEntry = entriesUnknownToPeer.get(pubkeyByteArray);
+
+			if (ourEntry != null && ourEntry.getTimestamp() == peersTradePresence.getTimestamp())
+				entriesUnknownToPeer.remove(pubkeyByteArray);
+		}
+
+		if (entriesUnknownToPeer.isEmpty())
+			return;
+
+		LOGGER.debug("Sending {} trade presences to peer {} after excluding their {} from known {}",
+				entriesUnknownToPeer.size(), peer, peersTradePresences.size(), knownCount
+		);
+
+		// Send complement to peer
+		List<TradePresenceData> safeTradePresences = List.copyOf(entriesUnknownToPeer.values());
+		Message responseMessage = new TradePresencesMessage(safeTradePresences);
+		//if (!peer.sendMessage(responseMessage)) {
+		//	peer.disconnect("failed to send TRADE_PRESENCES response");
+		//	return;
+		//}
+		peer.sendMessage(responseMessage);
+	}
+
+	public void onTradePresencesMessage(RNSPeer peer, Message message) {
+		TradePresencesMessage tradePresencesMessage = (TradePresencesMessage) message;
+
+		List<TradePresenceData> peersTradePresences = tradePresencesMessage.getTradePresences();
+
+		long now = NTP.getTime();
+		// Timestamps before this are too far into the past
+		long pastThreshold = now;
+		// Timestamps after this are too far into the future
+		long futureThreshold = now + PRESENCE_LIFETIME;
+
+		Map<ByteArray, Supplier<ACCT>> acctSuppliersByCodeHash = SupportedBlockchain.getAcctMap();
+
+		int newCount = 0;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			for (TradePresenceData peersTradePresence : peersTradePresences) {
+				long timestamp = peersTradePresence.getTimestamp();
+
+				// Ignore if timestamp is out of bounds
+				if (timestamp < pastThreshold || timestamp > futureThreshold) {
+					if (timestamp < pastThreshold)
+						LOGGER.trace("Ignoring trade presence {} from peer {} as timestamp {} is too old vs {}",
+								peersTradePresence.getAtAddress(), peer, timestamp, pastThreshold
+								);
+					else
+						LOGGER.trace("Ignoring trade presence {} from peer {} as timestamp {} is too new vs {}",
+								peersTradePresence.getAtAddress(), peer, timestamp, pastThreshold
+						);
+
+					continue;
+				}
+
+				ByteArray pubkeyByteArray = ByteArray.wrap(peersTradePresence.getPublicKey());
+
+				// Ignore if we've previously verified this timestamp+publickey combo or sent timestamp is older
+				TradePresenceData existingTradeData = this.safeAllTradePresencesByPubkey.get(pubkeyByteArray);
+				if (existingTradeData != null && timestamp <= existingTradeData.getTimestamp()) {
+					if (timestamp == existingTradeData.getTimestamp())
+						LOGGER.trace("Ignoring trade presence {} from peer {} as we have verified timestamp {} before",
+								peersTradePresence.getAtAddress(), peer, timestamp
+						);
+					else
+						LOGGER.trace("Ignoring trade presence {} from peer {} as timestamp {} is older than latest {}",
+								peersTradePresence.getAtAddress(), peer, timestamp, existingTradeData.getTimestamp()
+						);
+
+					continue;
+				}
+
+				// Check timestamp signature
+				byte[] timestampSignature = peersTradePresence.getSignature();
+				byte[] timestampBytes = Longs.toByteArray(timestamp);
+				byte[] publicKey = peersTradePresence.getPublicKey();
+				if (!Crypto.verify(publicKey, timestampSignature, timestampBytes)) {
+					LOGGER.trace("Ignoring trade presence {} from peer {} as signature failed to verify",
+							peersTradePresence.getAtAddress(), peer
+					);
+
+					continue;
+				}
+
+				ATData atData = repository.getATRepository().fromATAddress(peersTradePresence.getAtAddress());
+				if (atData == null || atData.getIsFrozen() || atData.getIsFinished()) {
+					if (atData == null)
+						LOGGER.trace("Ignoring trade presence {} from peer {} as AT doesn't exist",
+								peersTradePresence.getAtAddress(), peer
+						);
+					else
+						LOGGER.trace("Ignoring trade presence {} from peer {} as AT is frozen or finished",
+								peersTradePresence.getAtAddress(), peer
+						);
+
+					continue;
+				}
+
+				ByteArray atCodeHash = ByteArray.wrap(atData.getCodeHash());
+				Supplier<ACCT> acctSupplier = acctSuppliersByCodeHash.get(atCodeHash);
+				if (acctSupplier == null) {
+					LOGGER.trace("Ignoring trade presence {} from peer {} as AT isn't a known ACCT?",
+							peersTradePresence.getAtAddress(), peer
+					);
+
+					continue;
+				}
+
+				CrossChainTradeData tradeData = acctSupplier.get().populateTradeData(repository, atData);
+				if (tradeData == null) {
+					LOGGER.trace("Ignoring trade presence {} from peer {} as trade data not found?",
+							peersTradePresence.getAtAddress(), peer
+					);
+
+					continue;
+				}
+
+				// Convert signer's public key to address form
+				String signerAddress = peersTradePresence.getTradeAddress();
+
+				// Signer's public key (in address form) must match Bob's / Alice's trade public key (in address form)
+				if (!signerAddress.equals(tradeData.qortalCreatorTradeAddress) && !signerAddress.equals(tradeData.qortalPartnerAddress)) {
+					LOGGER.trace("Ignoring trade presence {} from peer {} as signer isn't Alice or Bob?",
+							peersTradePresence.getAtAddress(), peer
+					);
+
+					continue;
+				}
+
+				// This is new to us
+				this.allTradePresencesByPubkey.put(pubkeyByteArray, peersTradePresence);
+				++newCount;
+
+				LOGGER.trace("Added trade presence {} from peer {} with timestamp {}",
+						peersTradePresence.getAtAddress(), peer, timestamp
+				);
+
+				EventBus.INSTANCE.notify(new TradePresenceEvent(peersTradePresence));
+			}
+		} catch (DataException e) {
+			LOGGER.error("Couldn't process TRADE_PRESENCES message due to repository issue", e);
+		}
+
+		if (newCount > 0) {
+			LOGGER.debug("New trade presences: {}, all trade presences: {}", newCount, allTradePresencesByPubkey.size());
+			rebuildSafeAllTradePresences();
+		}
+	}
+
+	public void bridgePresence(long timestamp, byte[] publicKey, byte[] signature, String atAddress) {
+		long expiry = generateExpiry(timestamp);
+		ByteArray pubkeyByteArray = ByteArray.wrap(publicKey);
+
+		TradePresenceData fakeTradePresenceData = new TradePresenceData(expiry, publicKey, signature, atAddress);
+
+		// Only bridge if trade presence expiry timestamp is newer
+		TradePresenceData computedTradePresenceData = this.allTradePresencesByPubkey.compute(pubkeyByteArray, (k, v) ->
+				v == null || v.getTimestamp() < expiry ? fakeTradePresenceData : v
+		);
+
+		if (computedTradePresenceData == fakeTradePresenceData) {
+			LOGGER.trace("Bridged PRESENCE transaction for trade {} with timestamp {}", atAddress, expiry);
+			rebuildSafeAllTradePresences();
+
+			EventBus.INSTANCE.notify(new TradePresenceEvent(fakeTradePresenceData));
+		}
+	}
+
+	/** Decorates a CrossChainTradeData object with Alice / Bob trade-bot presence timestamp, if available. */
+	public void decorateTradeDataWithPresence(CrossChainTradeData crossChainTradeData) {
+		// Match by AT address, then check for Bob vs Alice
+		this.safeAllTradePresencesByPubkey.values().stream()
+				.filter(tradePresenceData -> tradePresenceData.getAtAddress().equals(crossChainTradeData.qortalAtAddress))
+				.forEach(tradePresenceData -> {
+					String signerAddress = tradePresenceData.getTradeAddress();
+
+					// Signer's public key (in address form) must match Bob's / Alice's trade public key (in address form)
+					if (signerAddress.equals(crossChainTradeData.qortalCreatorTradeAddress))
+						crossChainTradeData.creatorPresenceExpiry = tradePresenceData.getTimestamp();
+					else if (signerAddress.equals(crossChainTradeData.qortalPartnerAddress))
+						crossChainTradeData.partnerPresenceExpiry = tradePresenceData.getTimestamp();
+				});
+	}
+
+	/** Removes any trades that have had multiple failures */
+	public List<CrossChainTradeData> removeFailedTrades(Repository repository, List<CrossChainTradeData> crossChainTrades) {
+		Long now = NTP.getTime();
+		if (now == null) {
+			return crossChainTrades;
+		}
+
+		List<CrossChainTradeData> updatedCrossChainTrades = new ArrayList<>(crossChainTrades);
+		int getMaxTradeOfferAttempts = Settings.getInstance().getMaxTradeOfferAttempts();
+
+		for (CrossChainTradeData crossChainTradeData : crossChainTrades) {
+			// We only care about trades in the OFFERING state
+			if (crossChainTradeData.mode != AcctMode.OFFERING) {
+				failedTrades.remove(crossChainTradeData.qortalAtAddress);
+				validTrades.remove(crossChainTradeData.qortalAtAddress);
+				continue;
+			}
+
+			// Return recently cached values if they exist
+			Long failedTimestamp = failedTrades.get(crossChainTradeData.qortalAtAddress);
+			if (failedTimestamp != null && now - failedTimestamp < 60 * 60 * 1000L) {
+				updatedCrossChainTrades.remove(crossChainTradeData);
+				//LOGGER.info("Removing cached failed trade AT {}", crossChainTradeData.qortalAtAddress);
+				continue;
+			}
+			Long validTimestamp = validTrades.get(crossChainTradeData.qortalAtAddress);
+			if (validTimestamp != null && now - validTimestamp < 60 * 60 * 1000L) {
+				//LOGGER.info("NOT removing cached valid trade AT {}", crossChainTradeData.qortalAtAddress);
+				continue;
+			}
+
+			try {
+				List<TransactionData> transactions = repository.getTransactionRepository().getUnconfirmedTransactions(Arrays.asList(Transaction.TransactionType.MESSAGE), null, null, null, null);
+
+				for (TransactionData transactionData : transactions) {
+					// Treat as failed if buy attempt was more than 60 mins ago (as it's still in the OFFERING state)
+					if (transactionData.getRecipient().equals(crossChainTradeData.qortalCreatorTradeAddress) && now - transactionData.getTimestamp() > 60*60*1000L) {
+						failedTrades.put(crossChainTradeData.qortalAtAddress, now);
+						updatedCrossChainTrades.remove(crossChainTradeData);
+					} else {
+						validTrades.put(crossChainTradeData.qortalAtAddress, now);
+					}
+				}
+
+			} catch (DataException e) {
+				LOGGER.info("Unable to determine failed state of AT {}", crossChainTradeData.qortalAtAddress);
+            }
+		}
+
+		return updatedCrossChainTrades;
+	}
+
+	public boolean isFailedTrade(Repository repository, CrossChainTradeData crossChainTradeData) {
+		List<CrossChainTradeData> results = removeFailedTrades(repository, Arrays.asList(crossChainTradeData));
+		return results.isEmpty();
+	}
+
+	private long generateExpiry(long timestamp) {
+		return ((timestamp - 1) / EXPIRY_ROUNDING) * EXPIRY_ROUNDING + PRESENCE_LIFETIME;
+	}
+
+}

src/main/java/org/qortal/data/arbitrary/RNSArbitraryDirectConnectionInfo.java

@@ -0,0 +1,59 @@
+package org.qortal.data.arbitrary;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+public class RNSArbitraryDirectConnectionInfo {
+
+    private final byte[] signature;
+    private final String peerAddress;
+    private final List<byte[]> hashes;
+    private final long timestamp;
+
+    public RNSArbitraryDirectConnectionInfo(byte[] signature, String peerAddress, List<byte[]> hashes, long timestamp) {
+        this.signature = signature;
+        this.peerAddress = peerAddress;
+        this.hashes = hashes;
+        this.timestamp = timestamp;
+    }
+
+    public byte[] getSignature() {
+        return this.signature;
+    }
+
+    public String getPeerAddress() {
+        return this.peerAddress;
+    }
+
+    public List<byte[]> getHashes() {
+        return this.hashes;
+    }
+    
+    public long getTimestamp() {
+        return this.timestamp;
+    }
+
+    public int getHashCount() {
+        if (this.hashes == null) {
+            return 0;
+        }
+        return this.hashes.size();
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this)
+            return true;
+
+        if (!(other instanceof ArbitraryDirectConnectionInfo))
+            return false;
+
+        ArbitraryDirectConnectionInfo otherDirectConnectionInfo = (ArbitraryDirectConnectionInfo) other;
+
+        return Arrays.equals(this.signature, otherDirectConnectionInfo.getSignature())
+                && Objects.equals(this.peerAddress, otherDirectConnectionInfo.getPeerAddress())
+                && Objects.equals(this.hashes, otherDirectConnectionInfo.getHashes())
+                && Objects.equals(this.timestamp, otherDirectConnectionInfo.getTimestamp());
+    }
+}

src/main/java/org/qortal/data/arbitrary/RNSArbitraryFileListResponseInfo.java

@@ -0,0 +1,11 @@
+package org.qortal.data.arbitrary;
+
+import org.qortal.network.RNSPeer;
+
+public class RNSArbitraryFileListResponseInfo extends  RNSArbitraryRelayInfo {
+
+    public RNSArbitraryFileListResponseInfo(String hash58, String signature58, RNSPeer peer, Long timestamp, Long requestTime, Integer requestHops) {
+        super(hash58, signature58, peer, timestamp, requestTime, requestHops);
+    }
+
+}

src/main/java/org/qortal/data/arbitrary/RNSArbitraryRelayInfo.java

@@ -0,0 +1,73 @@
+package org.qortal.data.arbitrary;
+
+import org.qortal.network.RNSPeer;
+
+import java.util.Objects;
+
+public class RNSArbitraryRelayInfo {
+
+    private final String hash58;
+    private final String signature58;
+    private final RNSPeer peer;
+    private final Long timestamp;
+    private final Long requestTime;
+    private final Integer requestHops;
+
+    public RNSArbitraryRelayInfo(String hash58, String signature58, RNSPeer peer, Long timestamp, Long requestTime, Integer requestHops) {
+        this.hash58 = hash58;
+        this.signature58 = signature58;
+        this.peer = peer;
+        this.timestamp = timestamp;
+        this.requestTime = requestTime;
+        this.requestHops = requestHops;
+    }
+
+    public boolean isValid() {
+        return this.getHash58() != null && this.getSignature58() != null
+                && this.getPeer() != null && this.getTimestamp() != null;
+    }
+
+    public String getHash58() {
+        return this.hash58;
+    }
+
+    public String getSignature58() {
+        return signature58;
+    }
+
+    public RNSPeer getPeer() {
+        return peer;
+    }
+
+    public Long getTimestamp() {
+        return timestamp;
+    }
+
+    public Long getRequestTime() {
+        return this.requestTime;
+    }
+
+    public Integer getRequestHops() {
+        return this.requestHops;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s = %s, %s, %d", this.hash58, this.signature58, this.peer, this.timestamp);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this)
+            return true;
+
+        if (!(other instanceof RNSArbitraryRelayInfo))
+            return false;
+
+        RNSArbitraryRelayInfo otherRelayInfo = (RNSArbitraryRelayInfo) other;
+
+        return this.peer == otherRelayInfo.getPeer()
+                && Objects.equals(this.hash58, otherRelayInfo.getHash58())
+                && Objects.equals(this.signature58, otherRelayInfo.getSignature58());
+    }
+}

src/main/java/org/qortal/data/network/RNSPeerData.java

@@ -0,0 +1,117 @@
+package org.qortal.data.network;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import org.qortal.network.PeerAddress;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlTransient;
+import static org.apache.commons.codec.binary.Hex.encodeHexString;
+
+// All properties to be converted to JSON via JAXB
+@XmlAccessorType(XmlAccessType.FIELD)
+public class RNSPeerData {
+
+	//public static final int MAX_PEER_ADDRESS_SIZE = 255;
+
+	// Properties
+
+	//// Don't expose this via JAXB - use pretty getter instead
+	//@XmlTransient
+	//@Schema(hidden = true)
+	//private PeerAddress peerAddress;
+	private byte[] peerAddress;
+
+	private Long lastAttempted;
+	private Long lastConnected;
+	private Long lastMisbehaved;
+	private Long addedWhen;
+	private String addedBy;
+
+	/** The number of consecutive times we failed to sync with this peer */
+	private int failedSyncCount = 0;
+
+	// Constructors
+
+	// necessary for JAXB serialization
+	protected RNSPeerData() {
+	}
+
+	public RNSPeerData(byte[] peerAddress, Long lastAttempted, Long lastConnected, Long lastMisbehaved, Long addedWhen, String addedBy) {
+		this.peerAddress = peerAddress;
+		this.lastAttempted = lastAttempted;
+		this.lastConnected = lastConnected;
+		this.lastMisbehaved = lastMisbehaved;
+		this.addedWhen = addedWhen;
+		this.addedBy = addedBy;
+	}
+
+	public RNSPeerData(byte[] peerAddress, Long addedWhen, String addedBy) {
+		this(peerAddress, null, null, null, addedWhen, addedBy);
+	}
+
+	public RNSPeerData(byte[] peerAddress) {
+		this(peerAddress, null, null, null, null, null);
+	}
+
+	// Getters / setters
+
+	// Don't let JAXB use this getter
+	@XmlTransient
+	@Schema(hidden = true)
+	public byte[] getAddress() {
+		return this.peerAddress;
+	}
+
+	public Long getLastAttempted() {
+		return this.lastAttempted;
+	}
+
+	public void setLastAttempted(Long lastAttempted) {
+		this.lastAttempted = lastAttempted;
+	}
+
+	public Long getLastConnected() {
+		return this.lastConnected;
+	}
+
+	public void setLastConnected(Long lastConnected) {
+		this.lastConnected = lastConnected;
+	}
+
+	public Long getLastMisbehaved() {
+		return this.lastMisbehaved;
+	}
+
+	public void setLastMisbehaved(Long lastMisbehaved) {
+		this.lastMisbehaved = lastMisbehaved;
+	}
+
+	public Long getAddedWhen() {
+		return this.addedWhen;
+	}
+
+	public String getAddedBy() {
+		return this.addedBy;
+	}
+
+	public int getFailedSyncCount() {
+		return this.failedSyncCount;
+	}
+
+	public void setFailedSyncCount(int failedSyncCount) {
+		this.failedSyncCount = failedSyncCount;
+	}
+
+	public void incrementFailedSyncCount() {
+		this.failedSyncCount++;
+	}
+
+	// Pretty peerAddress getter for JAXB
+	@XmlElement(name = "address")
+	protected String getPrettyAddress() {
+		return encodeHexString(this.peerAddress);
+	}
+
+}

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

@@ -0,0 +1,31 @@
+package org.qortal.network;
+
+public class RNSCommon {
+
+    /**
+     * Destination application name
+     */
+    public static String MAINNET_APP_NAME = "qortal";      // production
+    public static String TESTNET_APP_NAME = "qortaltest";  // test net
+
+    /**
+     * Configuration path relative to the Qortal launch directory
+     */
+    public static String defaultRNSConfigPath = ".reticulum";
+    public static String defaultRNSConfigPathTestnet = ".reticulum_test";
+
+    /**
+     * Default config
+     */
+    public static String defaultRNSConfig = "reticulum_default_config.yml";
+    public static String defaultRNSConfigTestnet = "reticulum_default_testnet_config.yml";
+
+    ///**
+    // * Qortal RNS Destinations
+    // */
+    //public enum RNSDestinations {
+    //    BASE,
+    //    QDN;
+    //}
+    
+}

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

@@ -0,0 +1,845 @@
+package org.qortal.network;
+
+import io.reticulum.Reticulum;
+import io.reticulum.Transport;
+import io.reticulum.interfaces.ConnectionInterface;
+import io.reticulum.destination.Destination;
+import io.reticulum.destination.DestinationType;
+import io.reticulum.destination.Direction;
+import io.reticulum.destination.ProofStrategy;
+import io.reticulum.identity.Identity;
+import io.reticulum.link.Link;
+import io.reticulum.link.LinkStatus;
+//import io.reticulum.constant.LinkConstant;
+//import static io.reticulum.constant.ReticulumConstant.MTU;
+import io.reticulum.buffer.Buffer;
+import io.reticulum.buffer.BufferedRWPair;
+import io.reticulum.packet.Packet;
+import io.reticulum.packet.PacketReceipt;
+import io.reticulum.packet.PacketReceiptStatus;
+import io.reticulum.transport.AnnounceHandler;
+//import static io.reticulum.link.TeardownSession.DESTINATION_CLOSED;
+//import static io.reticulum.link.TeardownSession.INITIATOR_CLOSED;
+import static io.reticulum.link.TeardownSession.TIMEOUT;
+import static io.reticulum.link.LinkStatus.ACTIVE;
+import static io.reticulum.link.LinkStatus.STALE;
+import static io.reticulum.link.LinkStatus.CLOSED;
+import static io.reticulum.link.LinkStatus.PENDING;
+import static io.reticulum.link.LinkStatus.HANDSHAKE;
+//import static io.reticulum.packet.PacketContextType.LINKCLOSE;
+//import static io.reticulum.identity.IdentityKnownDestination.recall;
+import static io.reticulum.utils.IdentityUtils.concatArrays;
+//import static io.reticulum.constant.ReticulumConstant.TRUNCATED_HASHLENGTH;
+import static io.reticulum.constant.ReticulumConstant.CONFIG_FILE_NAME;
+import lombok.Data;
+//import lombok.Setter;
+//import lombok.Getter;
+import lombok.Synchronized;
+
+import org.qortal.repository.DataException;
+import org.qortal.settings.Settings;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.StandardCopyOption;
+import static java.nio.file.StandardOpenOption.CREATE;
+import static java.nio.file.StandardOpenOption.WRITE;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.channels.SelectionKey;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+//import static java.util.Objects.isNull;
+//import static java.util.Objects.isNull;
+import static java.util.Objects.nonNull;
+//import static org.apache.commons.lang3.BooleanUtils.isTrue;
+//import static org.apache.commons.lang3.BooleanUtils.isFalse;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Iterator;
+//import java.util.Random;
+//import java.util.Scanner;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicLong;
+//import java.util.concurrent.locks.Lock;
+//import java.util.concurrent.locks.ReentrantLock;
+import java.util.Objects;
+import java.util.function.Function;
+import java.time.Instant;
+
+import static org.apache.commons.codec.binary.Hex.encodeHexString;
+import org.qortal.utils.ExecuteProduceConsume;
+import org.qortal.utils.ExecuteProduceConsume.StatsSnapshot;
+import org.qortal.utils.NTP;
+import org.qortal.utils.NamedThreadFactory;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.BlockSummariesV2Message;
+import org.qortal.network.message.TransactionSignaturesMessage;
+import org.qortal.network.message.GetUnconfirmedTransactionsMessage;
+import org.qortal.network.task.RNSBroadcastTask;
+import org.qortal.network.task.RNSPrunePeersTask;
+import org.qortal.data.network.RNSPeerData;
+import org.qortal.controller.Controller;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.data.block.BlockData;
+import org.qortal.data.block.BlockSummaryData;
+import org.qortal.data.transaction.TransactionData;
+
+// logging
+import lombok.extern.slf4j.Slf4j;
+//import org.slf4j.Logger;
+//import org.slf4j.LoggerFactory;
+
+@Data
+@Slf4j
+public class RNSNetwork {
+
+    Reticulum reticulum;
+    //private static final String APP_NAME = "qortal";
+    static final String APP_NAME = Settings.getInstance().isTestNet() ? RNSCommon.TESTNET_APP_NAME: RNSCommon.MAINNET_APP_NAME;
+    //static final String defaultConfigPath = ".reticulum"; // if empty will look in Reticulums default paths
+    static final String defaultConfigPath = Settings.getInstance().isTestNet() ? RNSCommon.defaultRNSConfigPathTestnet: RNSCommon.defaultRNSConfigPath;
+    private final int MAX_PEERS = Settings.getInstance().getReticulumMaxPeers();
+    private final int MIN_DESIRED_PEERS = Settings.getInstance().getReticulumMinDesiredPeers();
+    // How long [ms] between pruning of peers
+	private long PRUNE_INTERVAL = 1 * 64 * 1000L; // ms;
+    
+    Identity serverIdentity;
+    public Destination baseDestination;
+    private volatile boolean isShuttingDown = false;
+
+    /**
+     * Maintain two lists for each subset of peers
+     *  => a synchronizedList, modified when peers are added/removed
+     *  => an immutable List, automatically rebuild to mirror synchronizedList, served to consumers
+     *  linkedPeers are "initiators" (containing initiator reticulum Link), actively doing work.
+     *  incomimgPeers are "non-initiators", the passive end of bidirectional Reticulum Buffers.
+     */
+    private final List<RNSPeer> linkedPeers = Collections.synchronizedList(new ArrayList<>());
+    private List<RNSPeer> immutableLinkedPeers = Collections.emptyList();
+    private final List<RNSPeer> incomingPeers = Collections.synchronizedList(new ArrayList<>());
+    private List<RNSPeer> immutableIncomingPeers = Collections.emptyList();
+
+    private final ExecuteProduceConsume rnsNetworkEPC;
+    private static final long NETWORK_EPC_KEEPALIVE = 1000L; // 1 second
+    private int totalThreadCount = 0;
+    private final int reticulumMaxNetworkThreadPoolSize = Settings.getInstance().getReticulumMaxNetworkThreadPoolSize();
+
+    // replicating a feature from Network.class needed in for base Message.java,
+    // just in case the classic TCP/IP Networking is turned off.
+    private static final byte[] MAINNET_MESSAGE_MAGIC = new byte[]{0x51, 0x4f, 0x52, 0x54}; // QORT
+    private static final byte[] TESTNET_MESSAGE_MAGIC = new byte[]{0x71, 0x6f, 0x72, 0x54}; // qorT
+    private static final int BROADCAST_CHAIN_TIP_DEPTH = 7; // (~1440 bytes)
+    /**
+     * How long between informational broadcasts to all ACTIVE peers, in milliseconds.
+     */
+    private static final long BROADCAST_INTERVAL = 30 * 1000L; // ms
+    /**
+     * Link low-level ping interval and timeout
+     */
+    private static final long LINK_PING_INTERVAL = 55 * 1000L; // ms
+    private static final long LINK_UNREACHABLE_TIMEOUT = 3 * LINK_PING_INTERVAL;
+
+    //private static final Logger logger = LoggerFactory.getLogger(RNSNetwork.class);
+    
+    // Constructor
+    private RNSNetwork () {
+        log.info("RNSNetwork constructor");
+        try {
+            //String configPath = new java.io.File(defaultConfigPath).getCanonicalPath();
+            log.info("creating config from {}", defaultConfigPath);
+            initConfig(defaultConfigPath);
+            //reticulum = new Reticulum(configPath);
+            reticulum = new Reticulum(defaultConfigPath);
+            var identitiesPath = reticulum.getStoragePath().resolve("identities");
+            if (Files.notExists(identitiesPath)) {
+                Files.createDirectories(identitiesPath);
+            }
+        } catch (IOException e) {
+            log.error("unable to create Reticulum network", e);
+        }
+        log.info("reticulum instance created");
+        log.info("reticulum instance created: {}", reticulum);
+
+        //        Settings.getInstance().getMaxRNSNetworkThreadPoolSize(),   // statically set to 5 below
+        ExecutorService RNSNetworkExecutor = new ThreadPoolExecutor(1,
+                reticulumMaxNetworkThreadPoolSize,
+                NETWORK_EPC_KEEPALIVE, TimeUnit.SECONDS,
+                new SynchronousQueue<Runnable>(),
+                new NamedThreadFactory("RNSNetwork-EPC", Settings.getInstance().getNetworkThreadPriority()));
+        rnsNetworkEPC = new RNSNetworkProcessor(RNSNetworkExecutor);
+    }
+
+    // Note: potentially create persistent serverIdentity (utility rnid) and load it from file
+    public void start() throws IOException, DataException {
+
+        // create identity either from file or new (creating new keys)
+        var serverIdentityPath = reticulum.getStoragePath().resolve("identities/"+APP_NAME);
+        if (Files.isReadable(serverIdentityPath)) {
+            serverIdentity = Identity.fromFile(serverIdentityPath);
+            log.info("server identity loaded from file {}", serverIdentityPath);
+        } else {
+            serverIdentity = new Identity();
+            log.info("APP_NAME: {}, storage path: {}", APP_NAME, serverIdentityPath);
+            log.info("new server identity created dynamically.");
+            // save it back to file by default for next start (possibly add setting to override)
+            try {
+                Files.write(serverIdentityPath, serverIdentity.getPrivateKey(), CREATE, WRITE);
+                log.info("serverIdentity written back to file");
+            } catch (IOException e) {
+                log.error("Error while saving serverIdentity to {}", serverIdentityPath, e);
+            }
+        }
+        log.debug("Server Identity: {}", serverIdentity.toString());
+
+        // show the ifac_size of the configured interfaces (debug code)
+        for (ConnectionInterface i: Transport.getInstance().getInterfaces() ) {
+            log.info("interface {}, length: {}", i.getInterfaceName(), i.getIfacSize());
+        }
+
+        baseDestination = new Destination(
+            serverIdentity,
+            Direction.IN,
+            DestinationType.SINGLE,
+            APP_NAME,
+            "core"
+        );
+        //// idea for other entry point (needs AnnounceHandler with appropriate aspect)
+        //dataDestination = new Destination(
+        //    serverIdentity,
+        //    Direction.IN,
+        //    DestinationType.SINGLE,
+        //    APP_NAME,
+        //    "qdn"
+        //);
+        log.info("Destination {} {} running", encodeHexString(baseDestination.getHash()), baseDestination.getName());
+   
+        baseDestination.setProofStrategy(ProofStrategy.PROVE_ALL);
+        baseDestination.setAcceptLinkRequests(true);
+        
+        baseDestination.setLinkEstablishedCallback(this::clientConnected);
+        Transport.getInstance().registerAnnounceHandler(new QAnnounceHandler());
+        log.debug("announceHandlers: {}", Transport.getInstance().getAnnounceHandlers());
+        // do a first announce
+        baseDestination.announce();
+        log.debug("Sent initial announce from {} ({})", encodeHexString(baseDestination.getHash()), baseDestination.getName());
+
+        // Start up first networking thread (the "server loop", the "Tasks engine")
+        rnsNetworkEPC.start();
+    }
+
+    private void initConfig(String configDir) throws IOException {
+        File configDir1 = new File(configDir);
+        if (!configDir1.exists()) {
+            configDir1.mkdir();
+        }
+        var configPath = Path.of(configDir1.getAbsolutePath());
+        Path configFile = configPath.resolve(CONFIG_FILE_NAME);
+
+        if (Files.notExists(configFile)) {
+            var defaultConfig = this.getClass().getClassLoader().getResourceAsStream(RNSCommon.defaultRNSConfig);
+            if (Settings.getInstance().isTestNet()) {
+                defaultConfig = this.getClass().getClassLoader().getResourceAsStream(RNSCommon.defaultRNSConfigTestnet);
+            }
+            Files.copy(defaultConfig, configFile, StandardCopyOption.REPLACE_EXISTING);
+        }
+    }
+
+    public void broadcast(Function<RNSPeer, Message> peerMessageBuilder) {
+        for (RNSPeer peer : getActiveImmutableLinkedPeers()) {
+            if (this.isShuttingDown) {
+                return;
+            }
+    
+            Message message = peerMessageBuilder.apply(peer);
+    
+            if (message == null) {
+                continue;
+            }
+    
+            var pl = peer.getPeerLink();
+            if (nonNull(pl) && (pl.getStatus() == ACTIVE)) {
+                peer.sendMessage(message);
+            }
+        }
+    }
+
+    public void broadcastOurChain() {
+        BlockData latestBlockData = Controller.getInstance().getChainTip();
+        int latestHeight = latestBlockData.getHeight();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            List<BlockSummaryData> latestBlockSummaries = repository.getBlockRepository().getBlockSummaries(latestHeight - BROADCAST_CHAIN_TIP_DEPTH, latestHeight);
+            Message latestBlockSummariesMessage = new BlockSummariesV2Message(latestBlockSummaries);
+
+            broadcast(broadcastPeer -> latestBlockSummariesMessage);
+        } catch (DataException e) {
+            log.warn("Couldn't broadcast our chain tip info", e);
+        }
+    }
+
+    public Message buildNewTransactionMessage(RNSPeer peer, TransactionData transactionData) {
+        // In V2 we send out transaction signature only and peers can decide whether to request the full transaction
+        return new TransactionSignaturesMessage(Collections.singletonList(transactionData.getSignature()));
+    }
+
+    public Message buildGetUnconfirmedTransactionsMessage(RNSPeer peer) {
+        return new GetUnconfirmedTransactionsMessage();
+    }
+
+    public void shutdown() {
+        this.isShuttingDown = true;
+        log.info("shutting down Reticulum");
+        
+        // gracefully close links of peers that point to us
+        for (RNSPeer p: incomingPeers) {
+            var pl = p.getPeerLink();
+            if (nonNull(pl) & (pl.getStatus() == ACTIVE)) {
+                p.sendCloseToRemote(pl);
+            }
+        }
+        // Disconnect peers gracefully and terminate Reticulum
+        for (RNSPeer p: linkedPeers) {
+            log.info("shutting down peer: {}", encodeHexString(p.getDestinationHash()));
+            //log.debug("peer: {}", p);
+            p.shutdown();
+            try {
+                TimeUnit.SECONDS.sleep(1); // allow for peers to disconnect gracefully
+            } catch (InterruptedException e) {
+                log.error("exception: ", e);
+            }
+            //var pl = p.getPeerLink();
+            //if (nonNull(pl) & (pl.getStatus() == ACTIVE)) {
+            //    pl.teardown();
+            //}
+        }
+        // Stop processing threads (the "server loop")
+        try {
+            if (!this.rnsNetworkEPC.shutdown(5000)) {
+                log.warn("RNSNetwork threads failed to terminate");
+            }
+        } catch (InterruptedException e) {
+            log.warn("Interrupted while waiting for RNS networking threads to terminate");
+        }
+        // Note: we still need to get the packet timeout callback to work...
+        reticulum.exitHandler();
+    }
+
+    public void sendCloseToRemote(Link link) {
+        if (nonNull(link)) {
+            var data = concatArrays("close::".getBytes(UTF_8),link.getDestination().getHash());
+            Packet closePacket = new Packet(link, data);
+            var packetReceipt = closePacket.send();
+            packetReceipt.setDeliveryCallback(this::closePacketDelivered);
+            packetReceipt.setTimeoutCallback(this::packetTimedOut);
+        } else {
+            log.debug("can't send to null link");
+        }
+    }
+
+    public void closePacketDelivered(PacketReceipt receipt) {
+        var rttString = "";
+        if (receipt.getStatus() == PacketReceiptStatus.DELIVERED) {
+            var rtt = receipt.getRtt();    // rtt (Java) is in miliseconds
+            //log.info("qqp - packetDelivered - rtt: {}", rtt);
+            if (rtt >= 1000) {
+                rtt = Math.round((float) rtt / 1000);
+                rttString = String.format("%d seconds", rtt);
+            } else {
+                rttString = String.format("%d miliseconds", rtt);
+            }
+            log.info("Shutdown packet confirmation received from {}, round-trip time is {}",
+                    encodeHexString(receipt.getDestination().getHash()), rttString);
+        }
+    }
+
+    public void packetTimedOut(PacketReceipt receipt) {
+        log.info("packet timed out, receipt status: {}", receipt.getStatus());
+    }
+
+    public void clientConnected(Link link) {
+        //link.setLinkClosedCallback(this::clientDisconnected);
+        //link.setPacketCallback(this::serverPacketReceived);
+        log.info("clientConnected - link hash: {}, {}", link.getHash(), encodeHexString(link.getHash()));
+        RNSPeer newPeer = new RNSPeer(link);
+        newPeer.setPeerLinkHash(link.getHash());
+        newPeer.setMessageMagic(getMessageMagic());
+        // make sure the peer has a channel and buffer
+        newPeer.getOrInitPeerBuffer();
+        addIncomingPeer(newPeer);
+        log.info("***> Client connected, link: {}", encodeHexString(link.getLinkId()));
+    }
+
+    public void clientDisconnected(Link link) {
+        log.info("***> Client disconnected");
+    }
+
+    public void serverPacketReceived(byte[] message, Packet packet) {
+        var msgText = new String(message, StandardCharsets.UTF_8);
+        log.info("Received data on link - message: {}, destinationHash: {}", msgText, encodeHexString(packet.getDestinationHash()));
+    }
+
+    //public void announceBaseDestination () {
+    //    getBaseDestination().announce();
+    //}
+
+    private class QAnnounceHandler implements AnnounceHandler {
+        @Override
+        public String getAspectFilter() {
+            return "qortal.core";
+        }
+
+        @Override
+        @Synchronized
+        public void receivedAnnounce(byte[] destinationHash, Identity announcedIdentity, byte[] appData) {
+            var peerExists = false;
+            var activePeerCount = 0; 
+
+            log.info("Received an announce from {}", encodeHexString(destinationHash));
+
+            if (nonNull(appData)) {
+                log.debug("The announce contained the following app data: {}", new String(appData, UTF_8));
+            }
+
+            // add to peer list if we can use more peers
+            //synchronized (this) {
+            var lps =  RNSNetwork.getInstance().getImmutableLinkedPeers();
+            for (RNSPeer p: lps) {
+                var pl = p.getPeerLink();
+                if ((nonNull(pl) && (pl.getStatus() == ACTIVE))) {
+                    activePeerCount = activePeerCount + 1;
+                }
+            }
+            if (activePeerCount < MAX_PEERS) {
+                for (RNSPeer p: lps) {
+                    if (Arrays.equals(p.getDestinationHash(), destinationHash)) {
+                        log.info("QAnnounceHandler - peer exists - found peer matching destinationHash");
+                        if (nonNull(p.getPeerLink())) {
+                            log.info("peer link: {}, status: {}",
+                                    encodeHexString(p.getPeerLink().getLinkId()), p.getPeerLink().getStatus());
+                        }
+                        peerExists = true;
+                        if (p.getPeerLink().getStatus() != ACTIVE) {
+                            p.getOrInitPeerLink();
+                        }
+                        break;
+                    } else {
+                        if (nonNull(p.getPeerLink())) {
+                            log.info("QAnnounceHandler - other peer - link: {}, status: {}",
+                                    encodeHexString(p.getPeerLink().getLinkId()), p.getPeerLink().getStatus());
+                            if (p.getPeerLink().getStatus() == CLOSED) {
+                                // mark peer for deletion on nexe pruning
+                                p.setDeleteMe(true);
+                            }
+                        } else {
+                            log.info("QAnnounceHandler - peer link is null");
+                        }
+                    }
+                }
+                if (!peerExists) {
+                    RNSPeer newPeer = new RNSPeer(destinationHash);
+                    newPeer.setServerIdentity(announcedIdentity);
+                    newPeer.setIsInitiator(true);
+                    newPeer.setMessageMagic(getMessageMagic());
+                    addLinkedPeer(newPeer);
+                    log.info("added new RNSPeer, destinationHash: {}", encodeHexString(destinationHash));
+                }
+            }
+            // Chance to announce instead of waiting for next pruning.
+            // Note: good in theory but leads to ping-pong of announces => not a good idea!
+            //maybeAnnounce(getBaseDestination());
+        }
+    }
+
+    // Main thread
+    class RNSNetworkProcessor extends ExecuteProduceConsume {
+
+        //private final Logger logger = LoggerFactory.getLogger(RNSNetworkProcessor.class);
+
+        private final AtomicLong nextConnectTaskTimestamp = new AtomicLong(0L); // ms - try first connect once NTP syncs
+        private final AtomicLong nextBroadcastTimestamp = new AtomicLong(0L); // ms - try first broadcast once NTP syncs
+        private final AtomicLong nextPingTimestamp = new AtomicLong(0L); // ms - try first low-level Ping
+        private final AtomicLong nextPruneTimestamp = new AtomicLong(0L); // ms - try first low-level Ping
+
+        private Iterator<SelectionKey> channelIterator = null;
+
+        RNSNetworkProcessor(ExecutorService executor) {
+            super(executor);
+            final Long now = NTP.getTime();
+            nextPruneTimestamp.set(now + PRUNE_INTERVAL/2);
+        }
+
+        @Override
+        protected void onSpawnFailure() {
+            // For debugging:
+            // ExecutorDumper.dump(this.executor, 3, ExecuteProduceConsume.class);
+        }
+
+        @Override
+        protected Task produceTask(boolean canBlock) throws InterruptedException {
+            Task task;
+
+            //// TODO: Needed? Figure out how to add pending messages in RNSPeer
+            ////        (RNSPeer: pendingMessages.offer(message))
+            //task = maybeProducePeerMessageTask();
+            //if (task != null) {
+            //    return task;
+            //}
+            
+            final Long now = NTP.getTime();
+            
+            // ping task (Link+Channel+Buffer)
+            task = maybeProducePeerPingTask(now);
+            if (task != null) {
+                return task;
+            }
+            
+            task = maybeProduceBroadcastTask(now);
+            if (task != null) {
+                return task;
+            }
+
+            //// Prune stuck/slow/old peers (moved from Controller)
+            //task = maybeProduceRNSPrunePeersTask(now);
+            //if (task != null) {
+            //    return task;
+            //}
+
+            return null;
+        }
+
+        ////private Task maybeProducePeerMessageTask() {
+        ////    return getImmutableConnectedPeers().stream()
+        ////            .map(Peer::getMessageTask)
+        ////            .filter(Objects::nonNull)
+        ////            .findFirst()
+        ////            .orElse(null);
+        ////}
+        ////private Task maybeProducePeerMessageTask() {
+        ////    return getImmutableIncomingPeers().stream()
+        ////            .map(RNSPeer::getMessageTask)
+        ////            .filter(RNSPeer::isAvailable)
+        ////            .findFirst()
+        ////            .orElse(null);
+        ////}
+        //// Note: we might not need this. All messages handled asynchronously in Reticulum
+        ////       (RNSPeer peerBufferReady callback)
+        //private Task maybeProducePeerMessageTask() {
+        //    return getActiveImmutableLinkedPeers().stream()
+        //            .map(RNSPeer::getMessageTask)
+        //            .filter(Objects::nonNull)
+        //            .findFirst()
+        //            .orElse(null);
+        //}
+
+        //private Task maybeProducePeerPingTask(Long now) {
+        //    return getImmutableHandshakedPeers().stream()
+        //            .map(peer -> peer.getPingTask(now))
+        //            .filter(Objects::nonNull)
+        //            .findFirst()
+        //            .orElse(null);
+        //}
+        private Task maybeProducePeerPingTask(Long now) {
+            //var ilp = getImmutableLinkedPeers().stream()
+            //        .map(peer -> peer.getPingTask(now))
+            //        .filter(Objects::nonNull)
+            //        .findFirst()
+            //        .orElse(null);
+            //if (nonNull(ilp)) {
+            //    log.info("ilp - {}", ilp);
+            //}
+            //return ilp;
+            return getActiveImmutableLinkedPeers().stream()
+                    .map(peer -> peer.getPingTask(now))
+                    .filter(Objects::nonNull)
+                    .findFirst()
+                    .orElse(null);
+        }
+        
+        private Task maybeProduceBroadcastTask(Long now) {
+            if (now == null || now < nextBroadcastTimestamp.get()) {
+                return null;
+            }
+            
+            nextBroadcastTimestamp.set(now + BROADCAST_INTERVAL);
+            return new RNSBroadcastTask();
+        }
+
+        private Task maybeProduceRNSPrunePeersTask(Long now) {
+            if (now == null || now < nextPruneTimestamp.get()) {
+                return null;
+            }
+            
+            nextPruneTimestamp.set(now + PRUNE_INTERVAL);
+            return new RNSPrunePeersTask();
+        }
+    }
+
+    private static class SingletonContainer {
+        private static final RNSNetwork INSTANCE = new RNSNetwork();
+    }
+
+    public static RNSNetwork getInstance() {
+        return SingletonContainer.INSTANCE;
+    }
+
+    public List<RNSPeer> getActiveImmutableLinkedPeers() {
+        List<RNSPeer> activePeers = Collections.synchronizedList(new ArrayList<>());
+        for (RNSPeer p: this.immutableLinkedPeers) {
+            if (nonNull(p.getPeerLink()) && (p.getPeerLink().getStatus() == ACTIVE)) {
+                activePeers.add(p);
+            }
+        }
+        return activePeers;
+    }
+
+    // note: we already have a lobok getter for this
+    //public List<RNSPeer> getImmutableLinkedPeers() {
+    //    return this.immutableLinkedPeers;
+    //}
+
+    public void addLinkedPeer(RNSPeer peer) {
+        this.linkedPeers.add(peer);
+        this.immutableLinkedPeers = List.copyOf(this.linkedPeers); // thread safe
+    }
+
+    public void removeLinkedPeer(RNSPeer peer) {
+        //if (nonNull(peer.getPeerBuffer())) {
+        //    peer.getPeerBuffer().close();
+        //}
+        if (nonNull(peer.getPeerLink())) {
+            peer.getPeerLink().teardown();
+        }
+        var p = this.linkedPeers.remove(this.linkedPeers.indexOf(peer)); // thread safe
+        this.immutableLinkedPeers = List.copyOf(this.linkedPeers);
+    }
+
+    // note: we already have a lobok getter for this
+    //public List<RNSPeer> getLinkedPeers() {
+    //    //synchronized(this.linkedPeers) {
+    //        //return new ArrayList<>(this.linkedPeers);
+    //        return this.linkedPeers;
+    //    //}
+    //}
+
+    public void addIncomingPeer(RNSPeer peer) {
+        this.incomingPeers.add(peer);
+        this.immutableIncomingPeers = List.copyOf(this.incomingPeers);
+    }
+
+    public void removeIncomingPeer(RNSPeer peer) {
+        if (nonNull(peer.getPeerLink())) {
+            peer.getPeerLink().teardown();
+        }
+        var p = this.incomingPeers.remove(this.incomingPeers.indexOf(peer));
+        this.immutableIncomingPeers = List.copyOf(this.incomingPeers);
+    }
+
+    // note: we already have a lobok getter for this
+    //public List<RNSPeer> getIncomingPeers() {
+    //    return this.incomingPeers;
+    //}
+    //public List<RNSPeer> getImmutableIncomingPeers() {
+    //    return this.immutableIncomingPeers;
+    //}
+
+    // TODO, methods for: getAvailablePeer
+
+    private Boolean isUnreachable(RNSPeer peer) {
+        var result = peer.getDeleteMe();
+        var now = Instant.now();
+        var peerLastAccessTimestamp = peer.getLastAccessTimestamp();
+        if (peerLastAccessTimestamp.isBefore(now.minusMillis(LINK_UNREACHABLE_TIMEOUT))) {
+            result = true;
+        }
+        return result;
+    }
+
+    public void peerMisbehaved(RNSPeer peer) {
+        RNSPeerData peerData = peer.getPeerData();
+        peerData.setLastMisbehaved(NTP.getTime());
+
+        //// Only update repository if outbound/initiator peer
+        //if (peer.getIsInitiator()) {
+        //    try (Repository repository = RepositoryManager.getRepository()) {
+        //        synchronized (this.allKnownPeers) {
+        //            repository.getNetworkRepository().save(peerData);
+        //            repository.saveChanges();
+        //        }
+        //    } catch (DataException e) {
+        //        log.warn("Repository issue while updating peer synchronization info", e);
+        //    }
+        //}
+    }
+
+    public List<RNSPeer> getNonActiveIncomingPeers() {
+        var ips = getIncomingPeers();
+        List<RNSPeer> result = Collections.synchronizedList(new ArrayList<>());
+        Link pl;
+        for (RNSPeer p: ips) {
+            pl = p.getPeerLink();
+            if (nonNull(pl)) {
+                if (pl.getStatus() != ACTIVE) {
+                    result.add(p);
+                }
+            } else {
+                result.add(p);
+            }
+        }
+        return result;
+    }
+
+    //@Synchronized
+    public void prunePeers() throws DataException {
+        // prune initiator peers
+        //var peerList = getImmutableLinkedPeers();
+        var initiatorPeerList = getImmutableLinkedPeers();
+        var initiatorActivePeerList = getActiveImmutableLinkedPeers();
+        var incomingPeerList = getImmutableIncomingPeers();
+        var numActiveIncomingPeers = incomingPeerList.size() - getNonActiveIncomingPeers().size();
+        log.info("number of links (linkedPeers (active) / incomingPeers (active) before prunig: {} ({}), {} ({})",
+                initiatorPeerList.size(), getActiveImmutableLinkedPeers().size(),
+                incomingPeerList.size(), numActiveIncomingPeers);
+        for (RNSPeer p: initiatorActivePeerList) {
+            var pLink = p.getOrInitPeerLink();
+            p.pingRemote();
+        }
+        for (RNSPeer p : initiatorPeerList) {
+            var pLink = p.getPeerLink();
+            if (nonNull(pLink)) {
+                if (p.getPeerTimedOut()) {
+                    // options: keep in case peer reconnects or remove => we'll remove it
+                    removeLinkedPeer(p);
+                    continue;
+                }
+                if (pLink.getStatus() == ACTIVE) {
+                    continue;
+                }
+                if ((pLink.getStatus() == CLOSED) || (p.getDeleteMe()))  {
+                    removeLinkedPeer(p);
+                    continue;
+                }
+                if (pLink.getStatus() == PENDING) {
+                    pLink.teardown();
+                    removeLinkedPeer(p);
+                    continue;
+                }
+            }
+        }
+        // prune non-initiator peers
+        List<RNSPeer> inaps = getNonActiveIncomingPeers();
+        incomingPeerList = this.incomingPeers;
+        for (RNSPeer p: incomingPeerList) {
+            var pLink = p.getOrInitPeerLink();
+            if (nonNull(pLink) && (pLink.getStatus() == ACTIVE)) {
+                // make false active links to timeout (and teardown in timeout callback)
+                // note: actual removal of peer happens on the following pruning run.
+                p.pingRemote();
+            }
+        }
+        for (RNSPeer p: inaps) {
+            var pLink = p.getPeerLink();
+            if (nonNull(pLink)) {
+                // could be eg. PENDING
+                pLink.teardown();
+            }
+            removeIncomingPeer(p);
+        }
+        initiatorPeerList = getImmutableLinkedPeers();
+        initiatorActivePeerList = getActiveImmutableLinkedPeers();
+        incomingPeerList = getImmutableIncomingPeers();
+        numActiveIncomingPeers = incomingPeerList.size() - getNonActiveIncomingPeers().size();
+        log.info("number of links (linkedPeers (active) / incomingPeers (active) after prunig: {} ({}), {} ({})",
+                initiatorPeerList.size(), getActiveImmutableLinkedPeers().size(),
+                incomingPeerList.size(), numActiveIncomingPeers);
+        maybeAnnounce(getBaseDestination());
+    }
+
+    public void maybeAnnounce(Destination d) {
+        var activePeers = getActiveImmutableLinkedPeers().size();
+        if (activePeers <= MIN_DESIRED_PEERS) {
+            log.info("Active peers ({}) <= desired peers ({}). Announcing", activePeers, MIN_DESIRED_PEERS);
+            d.announce();
+        }
+    }
+
+    /**
+     * Helper methods
+     */
+
+    public RNSPeer findPeerByLink(Link link) {
+        //List<RNSPeer> lps =  RNSNetwork.getInstance().getLinkedPeers();
+        List<RNSPeer> lps =  RNSNetwork.getInstance().getImmutableLinkedPeers();
+        RNSPeer peer = null;
+        for (RNSPeer p : lps) {
+            var pLink = p.getPeerLink();
+            if (nonNull(pLink)) {
+                if (Arrays.equals(pLink.getDestination().getHash(),link.getDestination().getHash())) {
+                    log.info("found peer matching destinationHash: {}", encodeHexString(link.getDestination().getHash()));
+                    peer = p;
+                    break;
+                }
+            }
+        }
+        return peer;
+    }
+
+    public RNSPeer findPeerByDestinationHash(byte[] dhash) {
+        //List<RNSPeer> lps =  RNSNetwork.getInstance().getLinkedPeers();
+        List<RNSPeer> lps =  RNSNetwork.getInstance().getImmutableLinkedPeers();
+        RNSPeer peer = null;
+        for (RNSPeer p : lps) {
+            if (Arrays.equals(p.getDestinationHash(), dhash)) {
+                log.info("found peer matching destinationHash: {}", encodeHexString(dhash));
+                peer = p;
+                break;
+            }
+        }
+        return peer;
+    }
+
+    //public void removePeer(RNSPeer peer) {
+    //    List<RNSPeer> peerList = this.linkedPeers;
+    //    if (nonNull(peer)) {
+    //        peerList.remove(peer);
+    //    }
+    //}
+
+    public byte[] getMessageMagic() {
+        return Settings.getInstance().isTestNet() ? TESTNET_MESSAGE_MAGIC : MAINNET_MESSAGE_MAGIC;
+    }
+
+    public String getOurNodeId() {
+        return this.serverIdentity.toString();
+    }
+
+    protected byte[] getOurPublicKey() {
+        return this.serverIdentity.getPublicKey();
+    }
+
+    // Network methods Reticulum implementation
+
+    /** Builds either (legacy) HeightV2Message or (newer) BlockSummariesV2Message, depending on peer version.
+     *
+     *  @return Message, or null if DataException was thrown.
+     */
+    public Message buildHeightOrChainTipInfo(RNSPeer peer) {
+        // peer only used for version check
+        int latestHeight = Controller.getInstance().getChainHeight();
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            List<BlockSummaryData> latestBlockSummaries = repository.getBlockRepository().getBlockSummaries(latestHeight - BROADCAST_CHAIN_TIP_DEPTH, latestHeight);
+            return new BlockSummariesV2Message(latestBlockSummaries);
+        } catch (DataException e) {
+            return null;
+        }
+    }
+
+}
+

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

@@ -0,0 +1,894 @@
+package org.qortal.network;
+
+//import org.slf4j.Logger;
+//import org.slf4j.LoggerFactory;
+
+import static java.util.Objects.isNull;
+import static java.util.Objects.nonNull;
+//import java.io.IOException;
+import java.time.Instant;
+import java.util.*;
+
+//import io.reticulum.Reticulum;
+//import org.qortal.network.RNSNetwork;
+import io.reticulum.link.Link;
+import io.reticulum.link.RequestReceipt;
+import io.reticulum.packet.PacketReceiptStatus;
+import io.reticulum.packet.Packet;
+import io.reticulum.packet.PacketReceipt;
+import io.reticulum.identity.Identity;
+import io.reticulum.channel.Channel;
+import io.reticulum.destination.Destination;
+import io.reticulum.destination.DestinationType;
+import io.reticulum.destination.Direction;
+import io.reticulum.destination.ProofStrategy;
+import io.reticulum.resource.Resource;
+import static io.reticulum.link.TeardownSession.INITIATOR_CLOSED;
+import static io.reticulum.link.TeardownSession.DESTINATION_CLOSED;
+import static io.reticulum.link.TeardownSession.TIMEOUT;
+import static io.reticulum.link.LinkStatus.ACTIVE;
+//import static io.reticulum.link.LinkStatus.CLOSED;
+import static io.reticulum.identity.IdentityKnownDestination.recall;
+//import static io.reticulum.identity.IdentityKnownDestination.recallAppData;
+import io.reticulum.buffer.Buffer;
+import io.reticulum.buffer.BufferedRWPair;
+import static io.reticulum.utils.IdentityUtils.concatArrays;
+
+import org.qortal.controller.Controller;
+import org.qortal.data.block.BlockSummaryData;
+import org.qortal.data.block.CommonBlockData;
+import org.qortal.data.network.RNSPeerData;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.MessageType;
+import org.qortal.network.message.PingMessage;
+import org.qortal.network.message.*;
+import org.qortal.network.message.MessageException;
+import org.qortal.network.task.RNSMessageTask;
+import org.qortal.network.task.RNSPingTask;
+import org.qortal.settings.Settings;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+import org.qortal.utils.NTP;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import static java.nio.charset.StandardCharsets.UTF_8;
+import java.util.concurrent.*;
+import java.util.Arrays;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.apache.commons.codec.binary.Hex.encodeHexString;
+import static org.apache.commons.lang3.ArrayUtils.subarray;
+import static org.apache.commons.lang3.BooleanUtils.isFalse;
+import static org.apache.commons.lang3.BooleanUtils.isTrue;
+
+import lombok.extern.slf4j.Slf4j;
+import lombok.Setter;
+import lombok.Data;
+import lombok.AccessLevel;
+//import lombok.Synchronized;
+//
+//import org.qortal.network.message.Message;
+//import org.qortal.network.message.MessageException;
+
+import java.util.concurrent.atomic.LongAdder;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import java.lang.IllegalStateException;
+
+@Data
+@Slf4j
+public class RNSPeer {
+
+    static final String APP_NAME = Settings.getInstance().isTestNet() ? RNSCommon.TESTNET_APP_NAME: RNSCommon.MAINNET_APP_NAME;
+    //static final String defaultConfigPath = new String(".reticulum");
+    //static final String defaultConfigPath = RNSCommon.defaultRNSConfigPath;
+
+    private byte[] destinationHash;   // remote destination hash
+    Destination peerDestination;      // OUT destination created for this
+    private Identity serverIdentity;
+    @Setter(AccessLevel.PACKAGE) private Instant creationTimestamp;
+    @Setter(AccessLevel.PACKAGE) private Instant lastAccessTimestamp;
+    @Setter(AccessLevel.PACKAGE) private Instant lastLinkProbeTimestamp;
+    Link peerLink;
+    byte[] peerLinkHash;
+    BufferedRWPair peerBuffer;
+    int receiveStreamId = 0;
+    int sendStreamId = 0;
+    private Boolean isInitiator;
+    private Boolean deleteMe = false;
+    //private Boolean isVacant = true;
+    private Long lastPacketRtt = null;
+    //private byte[] emptyBuffer = {0,0,0,0,0};
+
+    private Double requestResponseProgress;
+    @Setter(AccessLevel.PACKAGE) private Boolean peerTimedOut = false;
+
+    // for qortal networking
+    private static final int RESPONSE_TIMEOUT = 3000; // [ms]
+    private static final int PING_INTERVAL = 55_000; // [ms]
+    private static final long LINK_PING_INTERVAL = 55 * 1000L; // ms
+    private byte[] messageMagic;  // set in message creating classes
+    private Long lastPing = null;      // last (packet) ping roundtrip time [ms]
+    private Long lastPingSent = null;  // time last (packet) ping was sent, or null if not started.
+    @Setter(AccessLevel.PACKAGE) private Instant lastPingResponseReceived = null; // time last (packet) ping succeeded
+    private Map<Integer, BlockingQueue<Message>> replyQueues;
+    private LinkedBlockingQueue<Message> pendingMessages;
+    private boolean syncInProgress = false;
+    private RNSPeerData peerData = null;
+    private long linkEstablishedTime = -1L; // equivalent of (tcpip) Peer 'handshakeComplete'
+    // Versioning
+    public static final Pattern VERSION_PATTERN = Pattern.compile(Controller.VERSION_PREFIX
+            + "(\\d{1,3})\\.(\\d{1,5})\\.(\\d{1,5})");
+    /* Pending signature requests */
+    private List<byte[]> pendingSignatureRequests = Collections.synchronizedList(new ArrayList<>());
+    /**
+     * Latest block info as reported by peer.
+     */
+    private List<BlockSummaryData> peersChainTipData = Collections.emptyList();
+    /**
+     * Our common block with this peer
+     */
+    private CommonBlockData commonBlockData;
+    /**
+     * Last time we detected this peer as TOO_DIVERGENT
+     */
+    private Long lastTooDivergentTime;
+    ///**
+    // * Known starting sequences for data received over buffer
+    // */
+    //private byte[] SEQ_REQUEST_CONFIRM_ID = new byte[]{0x53, 0x52, 0x65, 0x71, 0x43, 0x49, 0x44}; // SReqCID
+    //private byte[] SEQ_RESPONSE_CONFIRM_ID = new byte[]{0x53, 0x52, 0x65, 0x73, 0x70, 0x43, 0x49, 0x44}; // SRespCID
+
+    // Message stats
+    private static class MessageStats {
+        public final LongAdder count = new LongAdder();
+        public final LongAdder totalBytes = new LongAdder();
+    }
+
+    private final Map<MessageType, RNSPeer.MessageStats> receivedMessageStats = new ConcurrentHashMap<>();
+    private final Map<MessageType, RNSPeer.MessageStats> sentMessageStats = new ConcurrentHashMap<>();
+
+    /**
+     * Constructor for initiator peers
+     */
+    public RNSPeer(byte[] dhash) {
+        this.destinationHash = dhash;
+        this.serverIdentity = recall(dhash);
+        initPeerLink();
+        //setCreationTimestamp(System.currentTimeMillis());
+        this.creationTimestamp = Instant.now();
+        //this.isVacant = true;
+        this.replyQueues = new ConcurrentHashMap<>();
+        this.pendingMessages = new LinkedBlockingQueue<>();
+        this.peerData = new RNSPeerData(dhash);
+    }
+
+    /**
+     * Constructor for non-initiator peers
+     */
+    public RNSPeer(Link link) {
+        this.peerLink = link;
+        //this.peerLinkId = link.getLinkId();
+        this.peerDestination = link.getDestination();
+        this.destinationHash = link.getDestination().getHash();
+        this.serverIdentity = link.getRemoteIdentity();
+
+        this.creationTimestamp = Instant.now();
+        this.lastAccessTimestamp = Instant.now();
+        this.lastLinkProbeTimestamp = null;
+        this.isInitiator = false;
+        //this.isVacant = false;
+
+        //this.peerLink.setLinkEstablishedCallback(this::linkEstablished);
+        //this.peerLink.setLinkClosedCallback(this::linkClosed);
+        //this.peerLink.setPacketCallback(this::linkPacketReceived);
+        this.peerData = new RNSPeerData(this.destinationHash);
+    }
+    public void initPeerLink() {
+        peerDestination = new Destination(
+            this.serverIdentity,
+            Direction.OUT, 
+            DestinationType.SINGLE,
+            APP_NAME,
+            "core"
+        );
+        peerDestination.setProofStrategy(ProofStrategy.PROVE_ALL);
+
+        this.creationTimestamp = Instant.now();
+        this.lastAccessTimestamp = Instant.now();
+        this.lastLinkProbeTimestamp = null;
+        this.isInitiator = true;
+
+        this.peerLink = new Link(peerDestination);
+
+        this.peerLink.setLinkEstablishedCallback(this::linkEstablished);
+        this.peerLink.setLinkClosedCallback(this::linkClosed);
+        this.peerLink.setPacketCallback(this::linkPacketReceived);
+    }
+
+    @Override
+    public String toString() {
+        // for messages we want an address-like string representation
+        if (nonNull(this.peerLink)) {
+            return this.getPeerLink().toString();
+        } else {
+            return encodeHexString(this.getDestinationHash());
+        }
+    }
+
+    public BufferedRWPair getOrInitPeerBuffer() {
+        var channel = this.peerLink.getChannel();
+        if (nonNull(this.peerBuffer)) {
+            //log.info("peerBuffer exists: {}, link status: {}", this.peerBuffer, this.peerLink.getStatus());
+            try {
+                log.trace("peerBuffer exists: {}, link status: {}", this.peerBuffer, this.peerLink.getStatus());
+            } catch (IllegalStateException e) {
+                // Exception thrown by Reticulum if the buffer is unusable (Channel, Link, etc)
+                // This is a chance to correct links status when doing a RNSPingTask
+                log.warn("can't establish Channel/Buffer (remote peer down?), closing link: {}");
+                this.peerBuffer.close();
+                this.peerLink.teardown();
+                this.peerLink = null;
+                //log.error("(handled) IllegalStateException - can't establish Channel/Buffer: {}", e);
+            }
+        }
+        else {
+            log.info("creating buffer - peerLink status: {}, channel: {}", this.peerLink.getStatus(), channel);
+            this.peerBuffer = Buffer.createBidirectionalBuffer(receiveStreamId, sendStreamId, channel, this::peerBufferReady);
+        }
+        return getPeerBuffer();
+    }
+
+    public Link getOrInitPeerLink() {
+        if (this.peerLink.getStatus() == ACTIVE) {
+            lastAccessTimestamp = Instant.now();
+            //return this.peerLink;
+        } else {
+            initPeerLink();
+        }
+        return this.peerLink;
+    }
+
+    public void shutdown() {
+        if (nonNull(this.peerLink)) {
+            log.info("shutdown - peerLink: {}, status: {}", peerLink, peerLink.getStatus());
+            if (peerLink.getStatus() == ACTIVE) {
+                if (nonNull(this.peerBuffer)) {
+                    this.peerBuffer.close();
+                    this.peerBuffer = null;
+                }
+                this.peerLink.teardown();
+            } else {
+                log.info("shutdown - status (non-ACTIVE): {}", peerLink.getStatus());
+            }
+            this.peerLink = null;
+        }
+        this.deleteMe = true;
+    }
+
+    public Channel getChannel() {
+        if (isNull(getPeerLink())) {
+            log.warn("link is null.");
+            return null;
+        }
+        setLastAccessTimestamp(Instant.now());
+        return getPeerLink().getChannel();
+    }
+
+    public Boolean getIsInitiator() {
+        return this.isInitiator;
+    }
+
+    /** Link callbacks */
+    public void linkEstablished(Link link) {
+        this.linkEstablishedTime = System.currentTimeMillis();
+        link.setLinkClosedCallback(this::linkClosed);
+        log.info("peerLink {} established (link: {}) with peer: hash - {}, link destination hash: {}", 
+            encodeHexString(peerLink.getLinkId()), encodeHexString(link.getLinkId()), encodeHexString(destinationHash),
+            encodeHexString(link.getDestination().getHash()));
+        if (isInitiator) {
+            startPings();
+        }
+    }
+    
+    public void linkClosed(Link link) {
+        if (link.getTeardownReason() == TIMEOUT) {
+            log.info("The link timed out");
+            this.peerTimedOut = true;
+            this.peerBuffer = null;
+        } else if (link.getTeardownReason() == INITIATOR_CLOSED) {
+            log.info("Link closed callback: The initiator closed the link");
+            log.info("peerLink {} closed (link: {}), link destination hash: {}",
+                encodeHexString(peerLink.getLinkId()), encodeHexString(link.getLinkId()), encodeHexString(link.getDestination().getHash()));
+            this.peerBuffer = null;
+        } else if (link.getTeardownReason() == DESTINATION_CLOSED) {
+            log.info("Link closed callback: The link was closed by the peer, removing peer");
+            log.info("peerLink {} closed (link: {}), link destination hash: {}",
+                encodeHexString(peerLink.getLinkId()), encodeHexString(link.getLinkId()), encodeHexString(link.getDestination().getHash()));
+            this.peerBuffer = null;
+        } else {
+            log.info("Link closed callback");
+        }
+    }
+    
+    public void linkPacketReceived(byte[] message, Packet packet) {
+        var msgText = new String(message, StandardCharsets.UTF_8);
+        if (msgText.equals("ping")) {
+            log.info("received ping on link");
+            this.lastLinkProbeTimestamp = Instant.now();
+        } else if (msgText.startsWith("close::")) {
+            var targetPeerHash = subarray(message, 7, message.length);
+            log.info("peer dest hash: {}, target hash: {}",
+                encodeHexString(destinationHash),
+                encodeHexString(targetPeerHash));
+            if (Arrays.equals(destinationHash, targetPeerHash)) {
+                log.info("closing link: {}", peerLink.getDestination().getHexHash());
+                if (nonNull(this.peerBuffer)) {
+                    this.peerBuffer.close();
+                    this.peerBuffer = null;
+                }
+                this.peerLink.teardown();
+            }
+        } else if (msgText.startsWith("open::")) {
+            var targetPeerHash = subarray(message, 7, message.length);
+            log.info("peer dest hash: {}, target hash: {}",
+                encodeHexString(destinationHash),
+                encodeHexString(targetPeerHash));
+            if (Arrays.equals(destinationHash, targetPeerHash)) {
+                log.info("closing link: {}", peerLink.getDestination().getHexHash());
+                getOrInitPeerLink();
+            }
+        }
+    }
+
+    /*
+     * Callback from buffer when buffer has data available
+     *
+     * :param readyBytes: The number of bytes ready to read
+     */
+    public void peerBufferReady(Integer readyBytes) {
+        // get the message data
+        byte[] data = this.peerBuffer.read(readyBytes);
+        ByteBuffer bb = ByteBuffer.wrap(data);
+        //log.info("data length: {}, MAGIC: {}, data: {}, ByteBuffer: {}", data.length, this.messageMagic, data, bb);
+        //log.info("data length: {}, MAGIC: {}, ByteBuffer: {}", data.length, this.messageMagic, bb);
+        //log.trace("peerBufferReady - data bytes: {}", data.length);
+        this.lastAccessTimestamp = Instant.now();
+
+        //if (ByteBuffer.wrap(data, 0, emptyBuffer.length).equals(ByteBuffer.wrap(emptyBuffer, 0, emptyBuffer.length))) {
+        //    log.info("peerBufferReady - empty buffer detected (length: {})", data.length);
+        //}
+        //else {
+        //if (Arrays.equals(SEQ_REQUEST_CONFIRM_ID, Arrays.copyOfRange(data, 0, SEQ_REQUEST_CONFIRM_ID.length))) {
+        //    // a non-initiator peer requested to confirm sending of a packet
+        //    var messageId = subarray(data, SEQ_REQUEST_CONFIRM_ID.length + 1, data.length);
+        //    log.info("received request to confirm message id, id: {}", messageId);
+        //    var confirmData = concatArrays(SEQ_RESPONSE_CONFIRM_ID, "::",data.getBytes(UTF_8), messageId.getBytes(UTF_8));
+        //    this.peerBuffer.write(confirmData);
+        //    this.peerBuffer.flush();
+        //} else if (Arrays.equals(SEQ_RESPONSE_CONFIRM_ID, Arrays.copyOfRange(data, 0, SEQ_RESPONSE_CONFIRM_ID.lenth))) {
+        //    // an initiator peer receiving the confirmation
+        //    var messageId = subarray(data, SEQ_RESPONSE_CONFIRM_ID.length + 1, data.length);
+        //    this.replyQueues.remove(messageId);
+        //} else {
+            try {
+                //log.info("***> creating message from {} bytes", data.length);
+                Message message = Message.fromByteBuffer(bb);
+                //log.info("*=> type {} message received ({} bytes): {}", message.getType(), data.length, message);
+                log.info("*=> type {} message received ({} bytes, id: {})", message.getType(), data.length, message.getId());
+
+                // Handle message based on type
+                switch (message.getType()) {
+                    // Do we need this ? (seems like a TCP scenario only thing)
+                    // Does any RNSPeer ever require an other RNSPeer's peer list?
+                    //case GET_PEERS:
+                    //    //onGetPeersMessage(peer, message);
+                    //    onGetRNSPeersMessage(peer, message);
+                    //    break;
+
+                    case PING:
+                        this.lastPingResponseReceived = Instant.now();
+                        if (isFalse(this.isInitiator)) {
+                            onPingMessage(this, message);
+                        }
+                        break;
+
+                    case PONG:
+                        log.trace("PONG received");
+                        addToQueue(message);  // as response in blocking queue for ping getResponse
+                        break;
+
+                    // Do we need this ? (no need to relay peer list...)
+                    //case PEERS_V2:
+                    //    onPeersV2Message(peer, message);
+                    //    break;
+
+                    case BLOCK_SUMMARIES:
+                        // from Synchronizer
+                        addToQueue(message);
+
+                    case BLOCK_SUMMARIES_V2:
+                        // from Synchronizer
+                        addToQueue(message);
+
+                    case SIGNATURES:
+                        // from Synchronizer
+                        addToQueue(message);
+
+                    case BLOCK:
+                        // from Synchronizer
+                        addToQueue(message);
+
+                    case BLOCK_V2:
+                        // from Synchronizer
+                        addToQueue(message);
+
+                    default:
+                        log.info("default - type {} message received ({} bytes)", message.getType(), data.length);
+                        // Bump up to controller for possible action
+                        addToQueue(message);
+                        Controller.getInstance().onRNSNetworkMessage(this, message);
+                        break;
+                }
+            } catch (MessageException e) {
+                //log.error("{} from peer {}", e.getMessage(), this);
+                log.error("{} from peer {}, closing link", e, this);
+                //log.info("{} from peer {}", e, this);
+                // don't take any chances:
+                // can happen if link is closed by peer in which case we close this side of the link
+                this.peerData.setLastMisbehaved(NTP.getTime());
+                shutdown();
+            }
+        //}
+    }
+
+    /**
+     * we need to queue all incoming messages that follow request/response
+     * with explicit handling of the response message.
+     */
+    public void addToQueue(Message message) {
+        if (message.getType() == MessageType.UNSUPPORTED) {
+            log.trace("discarding/skipping UNSUPPORTED message");
+            return;
+        }
+        BlockingQueue<Message> queue = this.replyQueues.get(message.getId());
+        if (queue != null) {
+            // Adding message to queue will unblock thread waiting for response
+            this.replyQueues.get(message.getId()).add(message);
+            // Consumed elsewhere (getResponseWithTimeout)
+            log.info("addToQueue - queue size: {}, message type: {} (id: {})", queue.size(), message.getType(), message.getId());
+        }
+        else if (!this.pendingMessages.offer(message)) {
+            log.info("[{}] Busy, no room to queue message from peer {} - discarding",
+                    this.peerLink, this);
+        }
+    }
+
+    /**
+     * Set a packet to remote with the message format "close::<our_destination_hash>"
+     * This method is only useful for non-initiator links to close the remote initiator.
+     *
+     * @param link
+     */
+    public void sendCloseToRemote(Link link) {
+        var baseDestination = RNSNetwork.getInstance().getBaseDestination();
+        if (nonNull(link) & (isFalse(link.isInitiator()))) {
+            // Note: if part of link we need to get the baseDesitination hash
+            //var data = concatArrays("close::".getBytes(UTF_8),link.getDestination().getHash());
+            var data = concatArrays("close::".getBytes(UTF_8), baseDestination.getHash());
+            Packet closePacket = new Packet(link, data);
+            var packetReceipt = closePacket.send();
+            packetReceipt.setDeliveryCallback(this::closePacketDelivered);
+            packetReceipt.setTimeout(1000L);
+            packetReceipt.setTimeoutCallback(this::packetTimedOut);
+        } else {
+            log.debug("can't send to null link");
+        }
+    }
+
+    /** PacketReceipt callbacks */
+    public void closePacketDelivered(PacketReceipt receipt) {
+        var rttString = new String("");
+        if (receipt.getStatus() == PacketReceiptStatus.DELIVERED) {
+            var rtt = receipt.getRtt();    // rtt (Java) is in milliseconds
+            this.lastPacketRtt = rtt;
+            if (rtt >= 1000) {
+                rtt = Math.round(rtt / 1000);
+                rttString = String.format("%d seconds", rtt);
+            } else {
+                rttString = String.format("%d miliseconds", rtt);
+            }
+            log.info("Shutdown packet confirmation received from {}, round-trip time is {}",
+                    encodeHexString(receipt.getDestination().getHash()), rttString);
+        }
+    }
+
+    public void packetDelivered(PacketReceipt receipt) {
+        var rttString = "";
+        //log.info("packet delivered callback, receipt: {}", receipt);
+        if (receipt.getStatus() == PacketReceiptStatus.DELIVERED) {
+            var rtt = receipt.getRtt();    // rtt (Java) is in milliseconds
+            this.lastPacketRtt = rtt;
+            //log.info("qqp - packetDelivered - rtt: {}", rtt);
+            if (rtt >= 1000) {
+                rtt = Math.round((float) rtt / 1000);
+                rttString = String.format("%d seconds", rtt);
+            } else {
+                rttString = String.format("%d milliseconds", rtt);
+            }
+            if (getIsInitiator()) {
+                // reporting round trip time in one direction is enough
+                log.info("Valid reply received from {}, round-trip time is {}",
+                        encodeHexString(receipt.getDestination().getHash()), rttString);
+            }
+            this.lastAccessTimestamp = Instant.now();
+        }
+    }
+
+    public void packetTimedOut(PacketReceipt receipt) {
+        //log.info("packet timed out, receipt status: {}", receipt.getStatus());
+        if (receipt.getStatus() == PacketReceiptStatus.FAILED) {
+            log.info("packet timed out, receipt status: {}", PacketReceiptStatus.FAILED);
+            this.peerTimedOut = true;
+            this.peerLink.teardown();
+        }
+        //this.peerTimedOut = true;
+        //this.peerLink.teardown();
+    }
+
+    /** Link Request callbacks */ 
+    public void linkRequestResponseReceived(RequestReceipt rr) {
+        log.info("Response received");
+    }
+
+    public void linkRequestResponseProgress(RequestReceipt rr) {
+        this.requestResponseProgress = rr.getProgress();
+        log.debug("Response progress set");
+    }
+
+    public void linkRequestFailed(RequestReceipt rr) {
+        log.error("Request failed");
+    }
+
+    /** Link Resource callbacks */
+    // Resource: allow arbitrary amounts of data to be passed over a link with
+    // sequencing, compression, coordination and checksumming handled automatically
+    //public Boolean linkResourceAdvertised(Resource resource) {
+    //    log.debug("Resource advertised");
+    //}
+    public void linkResourceTransferStarted(Resource resource) {
+        log.debug("Resource transfer started");
+    }
+    public void linkResourceTransferConcluded(Resource resource) {
+        log.debug("Resource transfer complete");
+    }
+
+    /** Utility methods */
+    public void pingRemote() {
+        var link = this.peerLink;
+        if (nonNull(link)) {
+            if (peerLink.getStatus() == ACTIVE) {
+                log.info("pinging remote (direct, 1 packet): {}", encodeHexString(link.getLinkId()));
+                var data = "ping".getBytes(UTF_8);
+                link.setPacketCallback(this::linkPacketReceived);
+                Packet pingPacket = new Packet(link, data);
+                PacketReceipt packetReceipt = pingPacket.send();
+                packetReceipt.setDeliveryCallback(this::packetDelivered);
+                // Note: don't setTimeout, we want it to timeout with FAIL if not deliverable
+                //packetReceipt.setTimeout(5000L);
+                packetReceipt.setTimeoutCallback(this::packetTimedOut);
+            } else {
+                log.info("can't send ping to a peer {} with (link) status: {}",
+                    encodeHexString(peerLink.getDestination().getHash()), peerLink.getStatus());
+            }
+        }
+    }
+
+    //public void shutdownLink(Link link) {
+    //    var data = "shutdown".getBytes(UTF_8);
+    //    Packet shutdownPacket = new Packet(link, data);
+    //    PacketReceipt packetReceipt = shutdownPacket.send();
+    //    packetReceipt.setTimeout(2000L);
+    //    packetReceipt.setTimeoutCallback(this::packetTimedOut);
+    //    packetReceipt.setDeliveryCallback(this::shutdownPacketDelivered);
+    //}
+
+    /** qortal networking specific (Tasks) */
+
+    private void onPingMessage(RNSPeer peer, Message message) {
+        PingMessage pingMessage = (PingMessage) message;
+    
+        try {
+            PongMessage pongMessage = new PongMessage();
+            pongMessage.setId(message.getId());  // use the ping message id (for ping getResponse)
+            this.peerBuffer.write(pongMessage.toBytes());
+            this.peerBuffer.flush();
+            this.lastAccessTimestamp = Instant.now();
+        } catch (MessageException e) {
+            //log.error("{} from peer {}", e.getMessage(), this);
+            log.error("{} from peer {}", e, this);
+        }
+    }
+
+    /**
+     * Send message to peer and await response, using default RESPONSE_TIMEOUT.
+     * <p>
+     * Message is assigned a random ID and sent.
+     * Responses are handled by registered callbacks.
+     * <p>
+     * Note: The method is called "get..." to match the original method name
+     *
+     * @param message message to send
+     * @return <code>Message</code> if valid response received; <code>null</code> if not or error/exception occurs
+     * @throws InterruptedException if interrupted while waiting
+     */
+    public Message getResponse(Message message) throws InterruptedException {
+        //log.info("RNSPingTask action - pinging peer {}", encodeHexString(getDestinationHash()));
+        return getResponseWithTimeout(message, RESPONSE_TIMEOUT);
+    }
+
+    /**
+     * Send message to peer and await response.
+     * <p>
+     * Message is assigned a random ID and sent.
+     * If a response with matching ID is received then it is returned to caller.
+     * <p>
+     * If no response with matching ID within timeout, or some other error/exception occurs,
+     * then return <code>null</code>.<br>
+     * (Assume peer will be rapidly disconnected after this).
+     *
+     * @param message message to send
+     * @return <code>Message</code> if valid response received; <code>null</code> if not or error/exception occurs
+     * @throws InterruptedException if interrupted while waiting
+     */
+    public Message getResponseWithTimeout(Message message, int timeout) throws InterruptedException {
+        BlockingQueue<Message> blockingQueue = new ArrayBlockingQueue<>(1);
+        // Assign random ID to this message
+        Random random = new Random();
+        int id;
+        do {
+            id = random.nextInt(Integer.MAX_VALUE - 1) + 1;
+
+            // Put queue into map (keyed by message ID) so we can poll for a response
+            // If putIfAbsent() doesn't return null, then this ID is already taken
+        } while (this.replyQueues.putIfAbsent(id, blockingQueue) != null);
+        message.setId(id);
+        //log.info("getResponse - before send {} message, random id is {}", message.getType(), id);
+
+        // Try to send message
+        if (!this.sendMessageWithTimeout(message, timeout)) {
+            this.replyQueues.remove(id);
+            return null;
+        }
+        //log.info("getResponse - after send");
+
+        try {
+            return blockingQueue.poll(timeout, TimeUnit.MILLISECONDS);
+        } finally {
+            this.replyQueues.remove(id);
+            //log.info("getResponse - regular - id removed from replyQueues");
+        }
+    }
+
+    /**
+     * Attempt to send Message to peer using the buffer and a custom timeout.
+     *
+     * @param message message to be sent
+     * @return <code>true</code> if message successfully sent; <code>false</code> otherwise
+     */
+    public boolean sendMessageWithTimeout(Message message, int timeout) {
+        try {
+            // send the message
+            log.trace("Sending {} message with ID {} to peer {}", message.getType().name(), message.getId(), this);
+            var peerBuffer = getOrInitPeerBuffer();
+            this.peerBuffer.write(message.toBytes());
+            this.peerBuffer.flush();
+            //// send a message to confirm receipt over the buffer
+            //var messageId = message.getId();
+            //var confirmData = concatArrays(SEQ_REQUEST_CONFIRM_ID,"::".getBytes(UTF_8), messageId.getBytes(UTF_8));
+            //this.peerBuffer.write(confirmData);
+            //this.peerBuffer.flush();
+            return true;
+        //} catch (InterruptedException e) {
+        //    // Send failure
+        //    return false;
+        } catch (IllegalStateException e) {
+            //log.warn("Can't write to buffer (remote buffer down?)");
+            this.peerLink.teardown();
+            this.peerBuffer = null;
+            log.error("IllegalStateException - can't write to buffer: {}", e);
+            return false;
+        } catch (MessageException e) {
+            log.error(e.getMessage(), e);
+            return false;
+        }
+    }
+
+    protected Task getMessageTask() {
+        /*
+         * If our peerLink is not in ACTIVE node and there is a message yet to be
+         * processed then don't produce another message task.
+         * This allows us to process remaining messages sequentially.
+         */
+        if (this.peerLink.getStatus() != ACTIVE) {
+            return null;
+        }
+
+        final Message nextMessage = this.pendingMessages.poll();
+
+        if (nextMessage == null) {
+            return null;
+        }
+
+        // Return a task to process message in queue
+        return new RNSMessageTask(this, nextMessage);
+    }
+
+    /**
+     * Send a Qortal message using a Reticulum Buffer
+     * 
+     * @param message message to be sent
+     * @return <code>true</code> if message successfully sent; <code>false</code> otherwise
+     */
+    //@Synchronized
+    public boolean sendMessage(Message message) {
+        try {
+            log.trace("Sending {} message with ID {} to peer {}", message.getType().name(), message.getId(), this.toString());
+            //log.info("Sending {} message with ID {} to peer {}", message.getType().name(), message.getId(), this.toString());
+            var peerBuffer = getOrInitPeerBuffer();
+            peerBuffer.write(message.toBytes());
+            peerBuffer.flush();
+            return true;
+        } catch (IllegalStateException e) {
+            this.peerLink.teardown();
+            this.peerBuffer = null;
+            log.error("IllegalStateException - can't write to buffer: {}", e);
+            return false;
+        } catch (MessageException e) {
+            log.error(e.getMessage(), e);
+            return false;
+        }
+    }
+
+    protected void startPings() {
+        log.trace("[{}] Enabling pings for peer {}",
+                peerLink.getDestination().getHexHash(), this.toString());
+        this.lastPingSent = NTP.getTime();
+    }
+
+    protected Task getPingTask(Long now) {
+        // Pings not enabled yet?
+        if (now == null || this.lastPingSent == null) {
+            return null;
+        }
+
+        // ping only possible over ACTIVE Link
+        if (nonNull(this.peerLink)) {
+            if (this.peerLink.getStatus() != ACTIVE) {
+                return null;
+            }
+        } else {
+            return null;
+        }
+
+        // Time to send another ping?
+        if (now < this.lastPingSent + PING_INTERVAL) {
+            return null; // Not yet
+        }
+
+        // Not strictly true, but prevents this peer from being immediately chosen again
+        this.lastPingSent = now;
+
+        return new RNSPingTask(this, now);
+    }
+
+    // low-level Link (packet) ping
+    protected Link getPingLinks(Long now) {
+        if (now == null || this.lastPingSent == null) {
+            return null;
+        }
+
+        // ping only possible over ACTIVE link
+        if (nonNull(this.peerLink)) {
+            if (this.peerLink.getStatus() != ACTIVE) {
+                return null;
+            }
+        } else {
+            return null;
+        }
+
+        if (now < this.lastPingSent + LINK_PING_INTERVAL) {
+            return null;
+        }
+
+        this.lastPingSent = now;
+
+        return this.peerLink;
+
+    }
+
+    // Peer methods reticulum implementations
+    public BlockSummaryData getChainTipData() {
+        List<BlockSummaryData> chainTipSummaries = this.peersChainTipData;
+
+        if (chainTipSummaries.isEmpty())
+            return null;
+
+        // Return last entry, which should have greatest height
+        return chainTipSummaries.get(chainTipSummaries.size() - 1);
+    }
+
+    public void setChainTipData(BlockSummaryData chainTipData) {
+        this.peersChainTipData = Collections.singletonList(chainTipData);
+    }
+
+    public List<BlockSummaryData> getChainTipSummaries() {
+        return this.peersChainTipData;
+    }
+
+    public void setChainTipSummaries(List<BlockSummaryData> chainTipSummaries) {
+        this.peersChainTipData = List.copyOf(chainTipSummaries);
+    }
+
+    public CommonBlockData getCommonBlockData() {
+        return this.commonBlockData;
+    }
+
+    public void setCommonBlockData(CommonBlockData commonBlockData) {
+        this.commonBlockData = commonBlockData;
+    }
+
+    // Common block data
+    public boolean canUseCachedCommonBlockData() {
+        BlockSummaryData peerChainTipData = this.getChainTipData();
+        if (peerChainTipData == null || peerChainTipData.getSignature() == null)
+            return false;
+         CommonBlockData commonBlockData = this.getCommonBlockData();
+        if (commonBlockData == null)
+            return false;
+         BlockSummaryData commonBlockChainTipData = commonBlockData.getChainTipData();
+        if (commonBlockChainTipData == null || commonBlockChainTipData.getSignature() == null)
+            return false;
+         if (!Arrays.equals(peerChainTipData.getSignature(), commonBlockChainTipData.getSignature()))
+            return false;
+         return true;
+    }
+
+    // Pending signature requests
+    public void addPendingSignatureRequest(byte[] signature) {
+        // Check if we already have this signature in the list
+        for (byte[] existingSignature : this.pendingSignatureRequests) {
+            if (Arrays.equals(existingSignature, signature )) {
+                return;
+            }
+        }
+        this.pendingSignatureRequests.add(signature);
+    }
+
+    public void removePendingSignatureRequest(byte[] signature) {
+        Iterator iterator = this.pendingSignatureRequests.iterator();
+        while (iterator.hasNext()) {
+            byte[] existingSignature = (byte[]) iterator.next();
+            if (Arrays.equals(existingSignature, signature)) {
+                iterator.remove();
+            }
+        }
+    }
+
+    public List<byte[]> getPendingSignatureRequests() {
+        return this.pendingSignatureRequests;
+    }
+
+    // Details used by API
+    public long getConnectionEstablishedTime() {
+        return linkEstablishedTime;
+    }
+
+    public long getConnectionAge() {
+        if (linkEstablishedTime > 0L) {
+            return System.currentTimeMillis() - linkEstablishedTime;
+        }
+        return linkEstablishedTime;
+    }
+}

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

@@ -0,0 +1,27 @@
+package org.qortal.network.task;
+
+import org.qortal.controller.Controller;
+//import org.qortal.network.RNSNetwork;
+//import org.qortal.repository.DataException;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+public class RNSPrunePeersTask implements Task {
+    public RNSPrunePeersTask() {
+    }
+
+    @Override
+    public String getName() {
+        return "PrunePeersTask";
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Controller.getInstance().doRNSPrunePeers();
+        //try {
+        //    log.debug("Pruning peers...");
+        //    RNSNetwork.getInstance().prunePeers();
+        //} catch (DataException e) {
+        //    log.warn(String.format("Repository issue when trying to prune peers: %s", e.getMessage()));
+        //}
+    }
+}

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

@@ -9,6 +9,8 @@ import java.io.IOException;
 import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 /**
  * Network message for sending over network, or unpacked data received from network.
@@ -33,6 +35,7 @@ import java.util.Arrays;
  * </p>
  */
 public abstract class Message {
+    private static final Logger LOGGER = LogManager.getLogger(Message.class);
 
 	// MAGIC(4) + TYPE(4) + HAS-ID(1) + ID?(4) + DATA-SIZE(4) + CHECKSUM?(4) + DATA?(*)
 	private static final int MAGIC_LENGTH = 4;
@@ -95,9 +98,11 @@ public abstract class Message {
 			byte[] messageMagic = new byte[MAGIC_LENGTH];
 			readOnlyBuffer.get(messageMagic);
 
-			if (!Arrays.equals(messageMagic, Network.getInstance().getMessageMagic()))
+			if (!Arrays.equals(messageMagic, Network.getInstance().getMessageMagic())) {
+				LOGGER.info("xyz - mM: {}, Network getMessageMagic: {}", messageMagic, Network.getInstance().getMessageMagic());
 				// Didn't receive correct Message "magic"
 				throw new MessageException("Received incorrect message 'magic'");
+			}
 
 			// Find supporting object
 			int typeValue = readOnlyBuffer.getInt();

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

@@ -0,0 +1,19 @@
+package org.qortal.network.task;
+
+import org.qortal.controller.Controller;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+public class RNSBroadcastTask implements Task {
+    public RNSBroadcastTask() {
+    }
+
+    @Override
+    public String getName() {
+        return "BroadcastTask";
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        Controller.getInstance().doRNSNetworkBroadcast();
+    }
+}

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

@@ -0,0 +1,30 @@
+package org.qortal.network.task;
+
+import org.qortal.network.RNSNetwork;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.Message;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+
+public class RNSMessageTask implements Task {
+    private final RNSPeer peer;
+    private final Message nextMessage;
+    private final String name;
+
+    public RNSMessageTask(RNSPeer peer, Message nextMessage) {
+        this.peer = peer;
+        this.nextMessage = nextMessage;
+        this.name = "MessageTask::" + peer + "::" + nextMessage.getType();
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        //RNSNetwork.getInstance().onMessage(peer, nextMessage);
+        // TODO: what do we do in the Reticulum case?
+        // Note: this is automatically handled (asynchronously) by the RNSPeer peerBufferReady callback
+    }
+}

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

@@ -0,0 +1,44 @@
+package org.qortal.network.task;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.network.RNSPeer;
+import org.qortal.network.message.Message;
+import org.qortal.network.message.MessageType;
+import org.qortal.network.message.PingMessage;
+import org.qortal.network.message.MessageException;
+import org.qortal.utils.ExecuteProduceConsume.Task;
+import org.qortal.utils.NTP;
+
+public class RNSPingTask implements Task {
+    private static final Logger LOGGER = LogManager.getLogger(PingTask.class);
+
+    private final RNSPeer peer;
+    private final Long now;
+    private final String name;
+
+    public RNSPingTask(RNSPeer peer, Long now) {
+        this.peer = peer;
+        this.now = now;
+        this.name = "PingTask::" + peer;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public void perform() throws InterruptedException {
+        PingMessage pingMessage = new PingMessage();
+
+        // Note: Even though getResponse would work, we can use
+        //       peer.sendMessage(pingMessage) using Reticulum buffer instead.
+        //       More efficient and saves room for other request/response tasks.
+        peer.getResponse(pingMessage);
+        //peer.sendMessage(pingMessage);
+
+        //// task is not over here (Reticulum is asynchronous)
+        //peer.setLastPing(NTP.getTime() - now);
+    }
+}

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

@@ -614,6 +614,17 @@ public class Settings {
 		}
 	}
 
+	// Related to mesh networking
+
+	/** Preferred network: "tcpip" or "reticulum" */
+	private String preferredNetwork = "reticulum";
+	/** Maximum number of Reticulum peers allowed. */
+	private int reticulumMaxPeers = 55;
+	/** Minimum number of Reticulum peers desired. */
+	private int reticulumMinDesiredPeers = 8;
+	/** Maximum number of task executor network threads */
+	private int reticulumMaxNetworkThreadPoolSize = 89;
+
 	// Constructors
 
 	private Settings() {
@@ -1371,6 +1382,22 @@ public class Settings {
 		return connectionPoolMonitorEnabled;
 	}
 
+	public String getPreferredNetwork () {
+		return this.preferredNetwork.toLowerCase(Locale.getDefault());
+	}
+
+	public int getReticulumMaxPeers() {
+		return this.reticulumMaxPeers;
+	}
+
+	public int getReticulumMinDesiredPeers() {
+		return this.reticulumMinDesiredPeers;
+	}
+
+	public int getReticulumMaxNetworkThreadPoolSize() {
+		return this.reticulumMaxNetworkThreadPoolSize;
+  	}
+
 	public int getBuildArbitraryResourcesBatchSize() {
 		return buildArbitraryResourcesBatchSize;
 	}

src/main/resources/reticulum_default_config.yml

@@ -0,0 +1,93 @@
+---
+# You should probably edit it to include any additional,
+# interfaces and settings you might need.
+
+# Only the most basic options are included in this default
+# configuration. To see a more verbose, and much longer,
+# configuration example, you can run the command:
+# rnsd --exampleconfig
+
+reticulum:
+
+  # If you enable Transport, your system will route traffic
+  # for other peers, pass announces and serve path requests.
+  # This should only be done for systems that are suited to
+  # act as transport nodes, ie. if they are stationary and
+  # always-on. This directive is optional and can be removed
+  # for brevity.
+
+  enable_transport: false
+
+  # By default, the first program to launch the Reticulum
+  # Network Stack will create a shared instance, that other
+  # programs can communicate with. Only the shared instance
+  # opens all the configured interfaces directly, and other
+  # local programs communicate with the shared instance over
+  # a local socket. This is completely transparent to the
+  # user, and should generally be turned on. This directive
+  # is optional and can be removed for brevity.
+
+  share_instance: false
+
+  # If you want to run multiple *different* shared instances
+  # on the same system, you will need to specify different
+  # shared instance ports for each. The defaults are given
+  # below, and again, these options can be left out if you
+  # don't need them.
+
+  #shared_instance_port: 37428
+  #instance_control_port: 37429
+  shared_instance_port: 37438
+  instance_control_port: 37439
+
+  # You can configure Reticulum to panic and forcibly close
+  # if an unrecoverable interface error occurs, such as the
+  # hardware device for an interface disappearing. This is
+  # an optional directive, and can be left out for brevity.
+  # This behaviour is disabled by default.
+
+  panic_on_interface_error: false
+
+
+# The interfaces section defines the physical and virtual
+# interfaces Reticulum will use to communicate on. This
+# section will contain examples for a variety of interface
+# types. You can modify these or use them as a basis for
+# your own config, or simply remove the unused ones.
+
+interfaces:
+
+  # This interface enables communication with other
+  # link-local Reticulum nodes over UDP. It does not
+  # need any functional IP infrastructure like routers
+  # or DHCP servers, but will require that at least link-
+  # local IPv6 is enabled in your operating system, which
+  # should be enabled by default in almost any OS. See
+  # the Reticulum Manual for more configuration options.
+  "Default Interface":
+    type: AutoInterface
+    enabled: true
+
+  # This interface enables communication with a "backbone"
+  # server over TCP.
+  # Note: others may be added for redundancy
+  "TCP Client Interface mobilefabrik":
+    type: TCPClientInterface
+    enabled: true
+    target_host: phantom.mobilefabrik.com
+    target_port: 4242
+    network_name: qortal
+
+  # This interface turns this Reticulum instance into a
+  # server other clients can connect to over TCP.
+  # To enable this instance to route traffic the above
+  # setting "enable_transport" needs to be set (to true).
+  # Note: this interface type is not yet supported by
+  #       reticulum-network-stack.
+  #"TCP Server Interface":
+  #  type: TCPServerInterface
+  #  enabled: true
+  #  listen_ip: 0.0.0.0
+  #  listen_port: 4242
+  #  network_name: qortal
+

src/main/resources/reticulum_default_testnet_config.yml

@@ -0,0 +1,93 @@
+---
+# You should probably edit it to include any additional,
+# interfaces and settings you might need.
+
+# Only the most basic options are included in this default
+# configuration. To see a more verbose, and much longer,
+# configuration example, you can run the command:
+# rnsd --exampleconfig
+
+reticulum:
+
+  # If you enable Transport, your system will route traffic
+  # for other peers, pass announces and serve path requests.
+  # This should only be done for systems that are suited to
+  # act as transport nodes, ie. if they are stationary and
+  # always-on. This directive is optional and can be removed
+  # for brevity.
+
+  enable_transport: false
+
+  # By default, the first program to launch the Reticulum
+  # Network Stack will create a shared instance, that other
+  # programs can communicate with. Only the shared instance
+  # opens all the configured interfaces directly, and other
+  # local programs communicate with the shared instance over
+  # a local socket. This is completely transparent to the
+  # user, and should generally be turned on. This directive
+  # is optional and can be removed for brevity.
+
+  share_instance: false
+
+  # If you want to run multiple *different* shared instances
+  # on the same system, you will need to specify different
+  # shared instance ports for each. The defaults are given
+  # below, and again, these options can be left out if you
+  # don't need them.
+
+  #shared_instance_port: 37428
+  #instance_control_port: 37429
+  shared_instance_port: 37438
+  instance_control_port: 37439
+
+  # You can configure Reticulum to panic and forcibly close
+  # if an unrecoverable interface error occurs, such as the
+  # hardware device for an interface disappearing. This is
+  # an optional directive, and can be left out for brevity.
+  # This behaviour is disabled by default.
+
+  panic_on_interface_error: false
+
+
+# The interfaces section defines the physical and virtual
+# interfaces Reticulum will use to communicate on. This
+# section will contain examples for a variety of interface
+# types. You can modify these or use them as a basis for
+# your own config, or simply remove the unused ones.
+
+interfaces:
+
+  # This interface enables communication with other
+  # link-local Reticulum nodes over UDP. It does not
+  # need any functional IP infrastructure like routers
+  # or DHCP servers, but will require that at least link-
+  # local IPv6 is enabled in your operating system, which
+  # should be enabled by default in almost any OS. See
+  # the Reticulum Manual for more configuration options.
+  "Default Interface":
+    type: AutoInterface
+    enabled: true
+
+  # This interface enables communication with a "backbone"
+  # server over TCP.
+  # Note: others may be added for redundancy
+  "TCP Client Interface mobilefabrik":
+    type: TCPClientInterface
+    enabled: true
+    target_host: phantom.mobilefabrik.com
+    target_port: 4242
+    network_name: qortaltest
+
+  # This interface turns this Reticulum instance into a
+  # server other clients can connect to over TCP.
+  # To enable this instance to route traffic the above
+  # setting "enable_transport" needs to be set (to true).
+  # Note: this interface type is not yet supported by
+  #       reticulum-network-stack.
+  #"TCP Server Interface":
+  #  type: TCPServerInterface
+  #  enabled: true
+  #  listen_ip: 0.0.0.0
+  #  listen_port: 4242
+  #  network_name: qortaltest
+

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

@@ -0,0 +1,70 @@
+package org.qortal.test.network;
+
+import org.apache.commons.lang3.StringUtils;
+//import org.junit.Before;
+//import org.junit.Ignore;
+import org.junit.Test;
+
+//import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+//import java.util.Arrays;
+
+import static io.reticulum.constant.ReticulumConstant.ETC_DIR;
+import static org.apache.commons.lang3.SystemUtils.USER_HOME;
+//import static org.junit.Assert.assertNotNull;
+
+class ReticulumTest {
+
+    //@Test
+    //void t() throws DecoderException {
+    //    System.out.println(Arrays.toString(Hex.decodeHex("adf54d882c9a9b80771eb4995d702d4a3e733391b2a0f53f416d9f907e55cff8")));
+    //    System.out.println(2 + 1 + (128 / 8) * 2);
+    //}
+
+    @Test
+    void path() {
+        System.out.println(initConfig(null));
+    }
+
+    //@Test
+    //void testConfigYamlParse() throws IOException {
+    //    var config = ConfigObj.initConfig(Path.of(getSystemClassLoader().getResource("reticulum.default.yml").getPath()));
+    //    assertNotNull(config);
+    //}
+
+    //@Test
+    //void testHKDF() {
+    //    var ifac_netname = "name";
+    //    var ifac_netkey = "password";
+    //    var ifacOrigin = new byte[]{};
+    //    ifacOrigin = ArrayUtils.addAll(ifacOrigin, getSha256Digest().digest(ifac_netname.getBytes(UTF_8)));
+    //    ifacOrigin = ArrayUtils.addAll(ifacOrigin, getSha256Digest().digest(ifac_netkey.getBytes(UTF_8)));
+    //
+    //    var ifacOriginHash = getSha256Digest().digest(ifacOrigin);
+    //
+    //    var HKDF = new HKDFBytesGenerator(new SHA256Digest());
+    //    HKDF.init(new HKDFParameters(ifacOriginHash, IFAC_SALT, new byte[0]));
+    //    var result = new byte[64];
+    //    var len = HKDF.generateBytes(result, 0, result.length);
+    //
+    //    assertNotNull(Hex.encodeHexString(result));
+    //}
+
+    private String initConfig(String configDir) {
+        if (StringUtils.isNotBlank(configDir)) {
+            return configDir;
+        } else {
+            if (Files.isDirectory(Path.of(ETC_DIR)) && Files.exists(Path.of(ETC_DIR, "config"))) {
+                return ETC_DIR;
+            } else if (
+                    Files.isDirectory(Path.of(USER_HOME, ".config", "reticulum"))
+                            && Files.exists(Path.of(USER_HOME, ".config", "reticulum", "config"))
+            ) {
+                return Path.of(USER_HOME, ".config", "reticulum").toString();
+            } else {
+                return Path.of(USER_HOME, ".reticulum").toString();
+            }
+        }
+    }
+}

start.sh

@@ -48,6 +48,9 @@ JVM_MEMORY_ARGS="-XX:MaxRAMPercentage=50 -XX:+UseG1GC -Xss1024k"
 nohup nice -n 20 java \
 	-Djava.net.preferIPv4Stack=false \
 	${JVM_MEMORY_ARGS} \
+  --add-opens=java.base/java.lang=ALL-UNNAMED \
+  --add-opens=java.base/java.net=ALL-UNNAMED \
+  --illegal-access=warn \
 	-jar qortal.jar \
 	1>run.log 2>&1 &