diff --git a/core/java/src/net/i2p/data/Hash.java b/core/java/src/net/i2p/data/Hash.java
index 23d466d68..555b00e22 100644
--- a/core/java/src/net/i2p/data/Hash.java
+++ b/core/java/src/net/i2p/data/Hash.java
@@ -104,4 +104,11 @@ public class Hash extends SimpleDataStructure {
         }
         return _base64ed;
     }
+
+    /**
+     *  @since 0.9.17
+     */
+    public static void clearCache() {
+        _cache.clear();
+    }
 }
diff --git a/core/java/src/net/i2p/data/PublicKey.java b/core/java/src/net/i2p/data/PublicKey.java
index ae5179ae4..aeb9e0096 100644
--- a/core/java/src/net/i2p/data/PublicKey.java
+++ b/core/java/src/net/i2p/data/PublicKey.java
@@ -68,4 +68,11 @@ public class PublicKey extends SimpleDataStructure {
     public int length() {
         return KEYSIZE_BYTES;
     }
+
+    /**
+     *  @since 0.9.17
+     */
+    public static void clearCache() {
+        _cache.clear();
+    }
 }
diff --git a/core/java/src/net/i2p/data/SDSCache.java b/core/java/src/net/i2p/data/SDSCache.java
index 9fecb6a14..ab7768014 100644
--- a/core/java/src/net/i2p/data/SDSCache.java
+++ b/core/java/src/net/i2p/data/SDSCache.java
@@ -91,9 +91,16 @@ public class SDSCache<V extends SimpleDataStructure> {
      */
     private class Shutdown implements Runnable {
         public void run() {
-            synchronized(_cache) {
-                _cache.clear();
-            }
+            clear();
+        }
+    }
+
+    /**
+     * @since 0.9.17
+     */
+    public void clear() {
+        synchronized(_cache) {
+            _cache.clear();
         }
     }
 
diff --git a/core/java/src/net/i2p/data/SigningPublicKey.java b/core/java/src/net/i2p/data/SigningPublicKey.java
index 50dba7213..386deadac 100644
--- a/core/java/src/net/i2p/data/SigningPublicKey.java
+++ b/core/java/src/net/i2p/data/SigningPublicKey.java
@@ -193,4 +193,11 @@ public class SigningPublicKey extends SimpleDataStructure {
         buf.append(']');
         return buf.toString();
     }
+
+    /**
+     *  @since 0.9.17
+     */
+    public static void clearCache() {
+        _cache.clear();
+    }
 }
diff --git a/history.txt b/history.txt
index ac488f87f..bfb03b9ad 100644
--- a/history.txt
+++ b/history.txt
@@ -1,4 +1,5 @@
 2014-11-12 zzz
+ * Data: Clear more caches when under memory pressure and at shutdown
  * Plugins: Fix bug in stopping a ClientApp plugin with $parameters in the args
 
 2014-11-09 zzz
diff --git a/router/java/src/net/i2p/router/Router.java b/router/java/src/net/i2p/router/Router.java
index bb597d2e2..ab8e7c38b 100644
--- a/router/java/src/net/i2p/router/Router.java
+++ b/router/java/src/net/i2p/router/Router.java
@@ -25,14 +25,18 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import gnu.getopt.Getopt;
 
+import net.i2p.crypto.SigUtil;
 import net.i2p.data.Base64;
 import net.i2p.data.Certificate;
 import net.i2p.data.DataFormatException;
 import net.i2p.data.DataHelper;
 import net.i2p.data.Destination;
-import net.i2p.data.router.RouterInfo;
+import net.i2p.data.Hash;
+import net.i2p.data.PublicKey;
 import net.i2p.data.SigningPrivateKey;
+import net.i2p.data.SigningPublicKey;
 import net.i2p.data.i2np.GarlicMessage;
+import net.i2p.data.router.RouterInfo;
 import net.i2p.router.message.GarlicMessageHandler;
 import net.i2p.router.networkdb.kademlia.FloodfillNetworkDatabaseFacade;
 import net.i2p.router.startup.CreateRouterInfoJob;
@@ -346,6 +350,10 @@ public class Router implements RouterClock.ClockShiftListener {
         SimpleByteCache.clearAll();
         Destination.clearCache();
         Translate.clearCache();
+        Hash.clearCache();
+        PublicKey.clearCache();
+        SigningPublicKey.clearCache();
+        SigUtil.clearCaches();
     }
 
     /**