Index: jackrabbit-core/src/test/repository/repository.xml
===================================================================
--- jackrabbit-core/src/test/repository/repository.xml	(revision 1483687)
+++ jackrabbit-core/src/test/repository/repository.xml	(working copy)
@@ -30,9 +30,7 @@
     <!--
         data store configuration
     -->
-    <DataStore class="org.apache.jackrabbit.core.data.FileDataStore">
-        <param name="secret" value="a very well kept secret"/>
-    </DataStore>
+    <DataStore class="org.apache.jackrabbit.core.data.FileDataStore"/>
     <!--
         sample database data store configuration
         <DataStore class="org.apache.jackrabbit.core.data.db.DbDataStore">
Index: jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/db/DbDataStore.java
===================================================================
--- jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/db/DbDataStore.java	(revision 1483687)
+++ jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/db/DbDataStore.java	(working copy)
@@ -16,22 +16,6 @@
  */
 package org.apache.jackrabbit.core.data.db;
 
-import org.apache.commons.io.input.CountingInputStream;
-import org.apache.jackrabbit.core.data.AbstractDataStore;
-import org.apache.jackrabbit.core.data.DataIdentifier;
-import org.apache.jackrabbit.core.data.DataRecord;
-import org.apache.jackrabbit.core.data.DataStoreException;
-import org.apache.jackrabbit.core.data.MultiDataStoreAware;
-import org.apache.jackrabbit.core.util.db.CheckSchemaOperation;
-import org.apache.jackrabbit.core.util.db.ConnectionFactory;
-import org.apache.jackrabbit.core.util.db.ConnectionHelper;
-import org.apache.jackrabbit.core.util.db.DatabaseAware;
-import org.apache.jackrabbit.core.util.db.DbUtility;
-import org.apache.jackrabbit.core.util.db.StreamWrapper;
-import org.apache.jackrabbit.util.Text;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.File;
@@ -51,10 +35,25 @@
 import java.util.Properties;
 import java.util.UUID;
 import java.util.WeakHashMap;
-
 import javax.jcr.RepositoryException;
 import javax.sql.DataSource;
 
+import org.apache.commons.io.input.CountingInputStream;
+import org.apache.jackrabbit.core.data.AbstractDataStore;
+import org.apache.jackrabbit.core.data.DataIdentifier;
+import org.apache.jackrabbit.core.data.DataRecord;
+import org.apache.jackrabbit.core.data.DataStoreException;
+import org.apache.jackrabbit.core.data.MultiDataStoreAware;
+import org.apache.jackrabbit.core.util.db.CheckSchemaOperation;
+import org.apache.jackrabbit.core.util.db.ConnectionFactory;
+import org.apache.jackrabbit.core.util.db.ConnectionHelper;
+import org.apache.jackrabbit.core.util.db.DatabaseAware;
+import org.apache.jackrabbit.core.util.db.DbUtility;
+import org.apache.jackrabbit.core.util.db.StreamWrapper;
+import org.apache.jackrabbit.util.Text;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * A data store implementation that stores the records in a database using JDBC.
  *
@@ -71,7 +70,7 @@
  *     &lt;param name="{@link #setCopyWhenReading(boolean) copyWhenReading}" value="true"/>
  *     &lt;param name="{@link #setTablePrefix(String) tablePrefix}" value=""/>
  *     &lt;param name="{@link #setSchemaObjectPrefix(String) schemaObjectPrefix}" value=""/>
- *     &lt;param name="{@link #setSchemaCheckEnabled(String) schemaCheckEnabled}" value="true"/>
+ *     &lt;param name="{@link #setSchemaCheckEnabled(boolean) schemaCheckEnabled}" value="true"/>
  * &lt/DataStore>
  * </pre>
  * <p>
@@ -306,7 +305,14 @@
         this.connectionFactory = connnectionFactory;
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public DataRecord addRecord(InputStream stream) throws DataStoreException {
+       return addRecord(null, stream);
+    }
+
+    private DataRecord addRecord(DataIdentifier identifier, InputStream stream) throws DataStoreException {
         InputStream fileInput = null;
         String tempId = null;
         ResultSet rs = null;
@@ -356,8 +362,9 @@
             // UPDATE DATASTORE SET DATA=? WHERE ID=?
             conHelper.exec(updateDataSQL, wrapper, tempId);
             long length = in.getByteCount();
-            DataIdentifier identifier =
-                    new DataIdentifier(encodeHexString(digest.digest()));
+            if (identifier == null) {
+                identifier = new DataIdentifier(encodeHexString(digest.digest()));
+            }
             usesIdentifier(identifier);
             String id = identifier.toString();
             long newModified;
@@ -1005,4 +1012,9 @@
     public void setDataSourceName(String dataSourceName) {
         this.dataSourceName = dataSourceName;
     }
+
+    @Override
+    protected DataRecord addReferenceKeyRecord(DataIdentifier referenceKeyIdentifier, InputStream inputStream) throws DataStoreException {
+        return addRecord(referenceKeyIdentifier, inputStream);
+    }
 }
Index: jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/AbstractDataStore.java
===================================================================
--- jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/AbstractDataStore.java	(revision 1483687)
+++ jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/AbstractDataStore.java	(working copy)
@@ -16,9 +16,15 @@
  */
 package org.apache.jackrabbit.core.data;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.security.SecureRandom;
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 
+import org.apache.commons.io.IOUtils;
+
 public abstract class AbstractDataStore implements DataStore {
 
     private static final String ALGORITHM = "HmacSHA1";
@@ -28,12 +34,6 @@
      */
     private static final char[] HEX = "0123456789abcdef".toCharArray();
 
-    private String secret;
-
-    public void setSecret(String secret) {
-        this.secret = secret;
-    }
-
     /**
      * Returns the hex encoding of the given bytes.
      *
@@ -66,20 +66,56 @@
     //---------------------------------------------------------< protected >--
 
     protected String getReferenceFromIdentifier(DataIdentifier identifier) {
-        if (secret != null) {
-            try {
-                String id = identifier.toString();
+        try {
+            String id = identifier.toString();
 
-                Mac mac = Mac.getInstance(ALGORITHM);
-                mac.init(new SecretKeySpec(secret.getBytes("UTF-8"), ALGORITHM));
-                byte[] hash = mac.doFinal(id.getBytes("UTF-8"));
+            Mac mac = Mac.getInstance(ALGORITHM);
+            mac.init(new SecretKeySpec(getReferenceKey(), ALGORITHM));
+            byte[] hash = mac.doFinal(id.getBytes("UTF-8"));
 
-                return id + ':' + encodeHexString(hash);
-            } catch (Exception e) {
-                // TODO: log a warning about this exception
-            }
+            return id + ':' + encodeHexString(hash);
+        } catch (Exception e) {
+            // TODO: log a warning about this exception
         }
         return null;
     }
 
-}
+    private synchronized byte[] getReferenceKey() {
+        DataIdentifier identifier = getReferenceKeyIdentifier();
+        InputStream stream = null;
+        try {
+            DataRecord dataRecord = getRecordIfStored(identifier);
+            if (dataRecord != null) {
+                stream = dataRecord.getStream();
+                return IOUtils.toByteArray(stream);
+            } else {
+                byte[] referenceKeyValue = generateReferenceKey();
+                stream = addReferenceKeyRecord(identifier, new ByteArrayInputStream(referenceKeyValue)).getStream();
+                return IOUtils.toByteArray(stream);
+            }
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        } finally {
+            if (stream != null) {
+                try {
+                    stream.close();
+                } catch (IOException e) {
+                    // do nothing
+                }
+            }
+        }
+    }
+
+    protected DataIdentifier getReferenceKeyIdentifier() {
+        return new DataIdentifier("referencekey");
+    }
+
+    protected byte[] generateReferenceKey() {
+        byte[] referenceKeyValue = new byte[256];
+        new SecureRandom().nextBytes(referenceKeyValue);
+        return referenceKeyValue;
+    }
+
+    protected abstract DataRecord addReferenceKeyRecord(DataIdentifier referenceKeyIdentifier, InputStream inputStream) throws DataStoreException;
+
+}
\ No newline at end of file
Index: jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java
===================================================================
--- jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java	(revision 1483687)
+++ jackrabbit-core/src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java	(working copy)
@@ -192,6 +192,11 @@
      * @throws DataStoreException if the record could not be created
      */
     public DataRecord addRecord(InputStream input) throws DataStoreException {
+        return addRecord(null, input);
+    }
+
+
+    private DataRecord addRecord(DataIdentifier identifier, InputStream input) throws DataStoreException {
         File temporary = null;
         try {
             temporary = newTemporaryFile();
@@ -208,8 +213,9 @@
             } finally {
                 output.close();
             }
-            DataIdentifier identifier =
-                    new DataIdentifier(encodeHexString(digest.digest()));
+            if (identifier == null) {
+                identifier = new DataIdentifier(encodeHexString(digest.digest()));
+            }
             File file;
 
             synchronized (this) {
@@ -470,4 +476,8 @@
             }
         }
     }
+
+    protected DataRecord addReferenceKeyRecord(DataIdentifier identifier, InputStream stream) throws DataStoreException {
+        return addRecord(identifier, stream);
+    }
 }