diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataBuilder.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataBuilder.java
index f8c95596..4db89688 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataBuilder.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataBuilder.java
@@ -10,6 +10,7 @@ import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.arbitrary.ArbitraryDataFile.ResourceIdType;
 import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -44,6 +45,7 @@ public class ArbitraryDataBuilder {
         this.validatePaths();
         this.findLatestSignature();
         this.buildLatestState();
+        this.cacheLatestSignature();
     }
 
     private void fetchTransactions() throws DataException {
@@ -163,6 +165,18 @@ public class ArbitraryDataBuilder {
         this.finalPath = pathBefore;
     }
 
+    private void cacheLatestSignature() throws IOException {
+        byte[] latestTransactionSignature = this.transactions.get(this.transactions.size()-1).getSignature();
+        if (latestTransactionSignature == null) {
+            throw new IllegalStateException("Missing latest transaction signature");
+        }
+
+        ArbitraryDataMetadataCache cache = new ArbitraryDataMetadataCache(this.finalPath);
+        cache.setSignature(latestTransactionSignature);
+        cache.setTimestamp(NTP.getTime());
+        cache.write();
+    }
+
     public Path getFinalPath() {
         return this.finalPath;
     }
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataCombiner.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataCombiner.java
index 3d3fbe9f..bf49ae99 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataCombiner.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataCombiner.java
@@ -87,7 +87,7 @@ public class ArbitraryDataCombiner {
             throw new IllegalStateException("No previous signature passed to the combiner");
         }
 
-        ArbitraryDataMetadata metadata = new ArbitraryDataMetadata(this.pathAfter);
+        ArbitraryDataMetadataPatch metadata = new ArbitraryDataMetadataPatch(this.pathAfter);
         metadata.read();
         byte[] previousSignature = metadata.getPreviousSignature();
         if (previousSignature == null) {
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
index 06976e72..84280738 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataDiff.java
@@ -214,7 +214,7 @@ public class ArbitraryDataDiff {
     }
 
     private void writeMetadata() throws IOException {
-        ArbitraryDataMetadata metadata = new ArbitraryDataMetadata(this.diffPath);
+        ArbitraryDataMetadataPatch metadata = new ArbitraryDataMetadataPatch(this.diffPath);
         metadata.setAddedPaths(this.addedPaths);
         metadata.setModifiedPaths(this.modifiedPaths);
         metadata.setRemovedPaths(this.removedPaths);
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
index 88b910f7..79fc5eaa 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataMerge.java
@@ -20,7 +20,7 @@ public class ArbitraryDataMerge {
     private Path pathAfter;
     private Path mergePath;
     private String identifier;
-    private ArbitraryDataMetadata metadata;
+    private ArbitraryDataMetadataPatch metadata;
 
     public ArbitraryDataMerge(Path pathBefore, Path pathAfter) {
         this.pathBefore = pathBefore;
@@ -70,7 +70,7 @@ public class ArbitraryDataMerge {
     }
 
     private void loadMetadata() throws IOException {
-        this.metadata = new ArbitraryDataMetadata(this.pathAfter);
+        this.metadata = new ArbitraryDataMetadataPatch(this.pathAfter);
         this.metadata.read();
     }
 
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadata.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadata.java
index 7de9cab2..5cf04b5d 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadata.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadata.java
@@ -13,31 +13,35 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.List;
 
 public class ArbitraryDataMetadata {
 
-    private static final Logger LOGGER = LogManager.getLogger(ArbitraryDataMetadata.class);
+    protected static final Logger LOGGER = LogManager.getLogger(ArbitraryDataMetadata.class);
 
-    private List<Path> addedPaths;
-    private List<Path> modifiedPaths;
-    private List<Path> removedPaths;
-    private Path filePath;
-    private Path qortalDirectoryPath;
-    private byte[] previousSignature;
+    protected Path filePath;
+    protected Path qortalDirectoryPath;
 
-    private String jsonString;
+    protected String jsonString;
 
     public ArbitraryDataMetadata(Path filePath) {
         this.filePath = filePath;
         this.qortalDirectoryPath = Paths.get(filePath.toString(), ".qortal");
-
-        this.addedPaths = new ArrayList<>();
-        this.modifiedPaths = new ArrayList<>();
-        this.removedPaths = new ArrayList<>();
     }
 
+    protected String fileName() {
+        // To be overridden
+        return null;
+    }
+
+    protected void readJson() {
+        // To be overridden
+    }
+
+    protected void buildJson() {
+        // To be overridden
+    }
+
+
     public void read() throws IOException {
         this.loadJson();
         this.readJson();
@@ -50,8 +54,8 @@ public class ArbitraryDataMetadata {
     }
 
 
-    private void loadJson() throws IOException {
-        Path path = Paths.get(this.qortalDirectoryPath.toString(), "patch");
+    protected void loadJson() throws IOException {
+        Path path = Paths.get(this.qortalDirectoryPath.toString(), this.fileName());
         File patchFile = new File(path.toString());
         if (!patchFile.exists()) {
             throw new IOException(String.format("Patch file doesn't exist: %s", path.toString()));
@@ -60,65 +64,7 @@ public class ArbitraryDataMetadata {
         this.jsonString = new String(Files.readAllBytes(path));
     }
 
-    private void readJson() {
-        if (this.jsonString == null) {
-            throw new IllegalStateException("Patch JSON string is null");
-        }
-
-        JSONObject patch = new JSONObject(this.jsonString);
-        if (patch.has("prevSig")) {
-            String prevSig = (String)patch.get("prevSig");
-            if (prevSig != null) {
-                this.previousSignature = Base58.decode(prevSig);
-            }
-        }
-        if (patch.has("added")) {
-            JSONArray added = (JSONArray) patch.get("added");
-            if (added != null) {
-                for (int i=0; i<added.length(); i++) {
-                    String pathString = (String)added.get(i);
-                    this.addedPaths.add(Paths.get(pathString));
-                }
-            }
-        }
-        if (patch.has("modified")) {
-            JSONArray modified = (JSONArray) patch.get("modified");
-            if (modified != null) {
-                for (int i=0; i<modified.length(); i++) {
-                    String pathString = (String)modified.get(i);
-                    this.modifiedPaths.add(Paths.get(pathString));
-                }
-            }
-        }
-        if (patch.has("removed")) {
-            JSONArray removed = (JSONArray) patch.get("removed");
-            if (removed != null) {
-                for (int i=0; i<removed.length(); i++) {
-                    String pathString = (String)removed.get(i);
-                    this.removedPaths.add(Paths.get(pathString));
-                }
-            }
-        }
-    }
-
-
-
-    private void buildJson() {
-        JSONArray addedPathsJson = new JSONArray(this.addedPaths);
-        JSONArray modifiedPathsJson = new JSONArray(this.modifiedPaths);
-        JSONArray removedPathsJson = new JSONArray(this.removedPaths);
-        String previousSignature58 = Base58.encode(this.previousSignature);
-
-        JSONObject patch = new JSONObject();
-        patch.put("prevSig", previousSignature58);
-        patch.put("added", addedPathsJson);
-        patch.put("modified", modifiedPathsJson);
-        patch.put("removed", removedPathsJson);
-
-        this.jsonString = patch.toString(2);
-    }
-
-    private void createQortalDirectory() {
+    protected void createQortalDirectory() {
         try {
             Files.createDirectories(this.qortalDirectoryPath);
         } catch (IOException e) {
@@ -126,46 +72,14 @@ public class ArbitraryDataMetadata {
         }
     }
 
-    private void writeToQortalPath() throws IOException {
-        Path patchPath = Paths.get(this.qortalDirectoryPath.toString(), "patch");
+    protected void writeToQortalPath() throws IOException {
+        Path patchPath = Paths.get(this.qortalDirectoryPath.toString(), this.fileName());
         BufferedWriter writer = new BufferedWriter(new FileWriter(patchPath.toString()));
         writer.write(this.jsonString);
         writer.close();
     }
 
 
-    public void setAddedPaths(List<Path> addedPaths) {
-        this.addedPaths = addedPaths;
-    }
-
-    public List<Path> getAddedPaths() {
-        return this.addedPaths;
-    }
-
-    public void setModifiedPaths(List<Path> modifiedPaths) {
-        this.modifiedPaths = modifiedPaths;
-    }
-
-    public List<Path> getModifiedPaths() {
-        return this.modifiedPaths;
-    }
-
-    public void setRemovedPaths(List<Path> removedPaths) {
-        this.removedPaths = removedPaths;
-    }
-
-    public List<Path> getRemovedPaths() {
-        return this.removedPaths;
-    }
-
-    public void setPreviousSignature(byte[] previousSignature) {
-        this.previousSignature = previousSignature;
-    }
-
-    public byte[] getPreviousSignature() {
-        return this.previousSignature;
-    }
-
     public String getJsonString() {
         return this.jsonString;
     }
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataCache.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataCache.java
new file mode 100644
index 00000000..cfe56593
--- /dev/null
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataCache.java
@@ -0,0 +1,69 @@
+package org.qortal.arbitrary;
+
+import org.json.JSONObject;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import java.nio.file.Path;
+
+public class ArbitraryDataMetadataCache extends ArbitraryDataMetadata {
+
+    private byte[] signature;
+    private long timestamp;
+
+    public ArbitraryDataMetadataCache(Path filePath) {
+        super(filePath);
+
+    }
+
+    @Override
+    protected String fileName() {
+        return "cache";
+    }
+
+    @Override
+    protected void readJson() {
+        if (this.jsonString == null) {
+            throw new IllegalStateException("Patch JSON string is null");
+        }
+
+        JSONObject cache = new JSONObject(this.jsonString);
+        if (cache.has("signature")) {
+            String sig = cache.getString("signature");
+            if (sig != null) {
+                this.signature = Base58.decode(sig);
+            }
+        }
+        if (cache.has("timestamp")) {
+            this.timestamp = cache.getLong("timestamp");
+        }
+    }
+
+    @Override
+    protected void buildJson() {
+        JSONObject patch = new JSONObject();
+        patch.put("signature", Base58.encode(this.signature));
+        patch.put("timestamp", this.timestamp);
+
+        this.jsonString = patch.toString(2);
+        LOGGER.info("Cache metadata: {}", this.jsonString);
+    }
+
+
+    public void setSignature(byte[] signature) {
+        this.signature = signature;
+    }
+
+    public byte[] getSignature() {
+        return this.signature;
+    }
+
+    public void setTimestamp(long timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public long getTimestamp() {
+        return this.timestamp;
+    }
+
+}
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataPatch.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataPatch.java
new file mode 100644
index 00000000..2c1f4a7c
--- /dev/null
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataMetadataPatch.java
@@ -0,0 +1,119 @@
+package org.qortal.arbitrary;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.qortal.utils.Base58;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ArbitraryDataMetadataPatch extends ArbitraryDataMetadata {
+
+    private List<Path> addedPaths;
+    private List<Path> modifiedPaths;
+    private List<Path> removedPaths;
+    private byte[] previousSignature;
+
+    public ArbitraryDataMetadataPatch(Path filePath) {
+        super(filePath);
+
+        this.addedPaths = new ArrayList<>();
+        this.modifiedPaths = new ArrayList<>();
+        this.removedPaths = new ArrayList<>();
+    }
+
+    @Override
+    protected String fileName() {
+        return "patch";
+    }
+
+    @Override
+    protected void readJson() {
+        if (this.jsonString == null) {
+            throw new IllegalStateException("Patch JSON string is null");
+        }
+
+        JSONObject patch = new JSONObject(this.jsonString);
+        if (patch.has("prevSig")) {
+            String prevSig = patch.getString("prevSig");
+            if (prevSig != null) {
+                this.previousSignature = Base58.decode(prevSig);
+            }
+        }
+        if (patch.has("added")) {
+            JSONArray added = (JSONArray) patch.get("added");
+            if (added != null) {
+                for (int i=0; i<added.length(); i++) {
+                    String pathString = added.getString(i);
+                    this.addedPaths.add(Paths.get(pathString));
+                }
+            }
+        }
+        if (patch.has("modified")) {
+            JSONArray modified = (JSONArray) patch.get("modified");
+            if (modified != null) {
+                for (int i=0; i<modified.length(); i++) {
+                    String pathString = modified.getString(i);
+                    this.modifiedPaths.add(Paths.get(pathString));
+                }
+            }
+        }
+        if (patch.has("removed")) {
+            JSONArray removed = (JSONArray) patch.get("removed");
+            if (removed != null) {
+                for (int i=0; i<removed.length(); i++) {
+                    String pathString = removed.getString(i);
+                    this.removedPaths.add(Paths.get(pathString));
+                }
+            }
+        }
+    }
+
+    @Override
+    protected void buildJson() {
+        JSONObject patch = new JSONObject();
+        patch.put("prevSig", Base58.encode(this.previousSignature));
+        patch.put("added", new JSONArray(this.addedPaths));
+        patch.put("modified", new JSONArray(this.modifiedPaths));
+        patch.put("removed", new JSONArray(this.removedPaths));
+
+        this.jsonString = patch.toString(2);
+        LOGGER.info("Patch metadata: {}", this.jsonString);
+    }
+
+
+    public void setAddedPaths(List<Path> addedPaths) {
+        this.addedPaths = addedPaths;
+    }
+
+    public List<Path> getAddedPaths() {
+        return this.addedPaths;
+    }
+
+    public void setModifiedPaths(List<Path> modifiedPaths) {
+        this.modifiedPaths = modifiedPaths;
+    }
+
+    public List<Path> getModifiedPaths() {
+        return this.modifiedPaths;
+    }
+
+    public void setRemovedPaths(List<Path> removedPaths) {
+        this.removedPaths = removedPaths;
+    }
+
+    public List<Path> getRemovedPaths() {
+        return this.removedPaths;
+    }
+
+    public void setPreviousSignature(byte[] previousSignature) {
+        this.previousSignature = previousSignature;
+    }
+
+    public byte[] getPreviousSignature() {
+        return this.previousSignature;
+    }
+
+}