diff --git a/framework/Core/lib/Horde/Session.php b/framework/Core/lib/Horde/Session.php
index 08fee53215f..25abba202c8 100644
--- a/framework/Core/lib/Horde/Session.php
+++ b/framework/Core/lib/Horde/Session.php
@@ -47,6 +47,7 @@ class Horde_Session
 
     const NONCE_ID = 'session_nonce'; /* @since 2.11.0 */
     const TOKEN_ID = 'session_token';
+    const UNIQUE_ID = 'unique_id'; /* @since 2.12.0 */
 
     /**
      * Maximum size of the pruneable data store.
@@ -579,6 +580,24 @@ public function checkNonce($nonce)
         $this->set('horde', self::NONCE_ID, array_values($nonces));
     }
 
+    /* Unique ID. */
+
+    /**
+     * Return a unique identifier for this session.
+     *
+     * @since 2.12.0
+     *
+     * @return string  Unique ID.
+     */
+    public function getUniqueId()
+    {
+        if (($id = $this->get('horde', self::UNIQUE_ID)) === null) {
+            $id = strval(new Horde_Support_Randomid());
+            $this->set('horde', self::UNIQUE_ID, $id);
+        }
+
+        return $id;
+    }
 
     /* Session object storage. */
 
diff --git a/framework/Core/package.xml b/framework/Core/package.xml
index 4ceb48527cf..d80be452f8a 100644
--- a/framework/Core/package.xml
+++ b/framework/Core/package.xml
@@ -39,6 +39,7 @@
  </stability>
  <license uri="http://www.horde.org/licenses/lgpl21">LGPL-2.1</license>
  <notes>
+* [mms] Add Horde_Session#getUniqueId().
 * [mms] Add abstracted web notifications interface to the Horde_Notification system.
 * [mms] Upgrade prototype.js to most recent git version (0df1298f807818471209b7e7971c3480e36a4f71).
 * [mjr] Fix issue that causes enter to submit the form when inside the pretty autocompleter (Bug #12923).
@@ -3367,6 +3368,7 @@
    <date>2014-04-04</date>
    <license uri="http://www.horde.org/licenses/lgpl21">LGPL-2.1</license>
    <notes>
+* [mms] Add Horde_Session#getUniqueId().
 * [mms] Add abstracted web notifications interface to the Horde_Notification system.
 * [mms] Upgrade prototype.js to most recent git version (0df1298f807818471209b7e7971c3480e36a4f71).
 * [mjr] Fix issue that causes enter to submit the form when inside the pretty autocompleter (Bug #12923).