diff --git a/application/libraries/MY_Session.php b/application/libraries/MY_Session.php
new file mode 100644
index 0000000..58c9f97
--- /dev/null
+++ b/application/libraries/MY_Session.php
@@ -0,0 +1,84 @@
+<?php defined('BASEPATH') || exit("No direct script access allowed");
+
+/**
+ * Extends CI's session class.
+ *
+ * @author Eike Foken
+ */
+class MY_Session extends CI_Session {
+
+    /**
+     * Calls the parent constructor.
+     */
+    public function __construct() {
+        parent::__construct();
+    }
+
+    /**
+     * Generates a random and unique session ID.
+     *
+     * @return string
+     */
+    private function generateHash() {
+        return sha1(uniqid(microtime() . $this->CI->input->ip_address(), true));
+    }
+
+    /**
+     * Creates a new session.
+     */
+    public function sess_create() {
+        $this->userdata = array(
+        	'session_id' => $this->generateHash(),
+        	'ip_address' => $this->CI->input->ip_address(),
+        	'user_agent' => substr($this->CI->input->user_agent(), 0, 50),
+        	'last_activity' => $this->now
+        );
+
+        // save data to the DB if needed
+        if ($this->sess_use_database === true) {
+            $this->CI->db->insert($this->sess_table_name, $this->userdata);
+        }
+
+        // write the cookie
+        $this->_set_cookie();
+    }
+
+    /**
+     * Updates an existing session.
+     */
+    public function sess_update() {
+        if ($this->userdata['last_activity'] + $this->sess_time_to_update >= $this->now) {
+            return;
+        }
+
+        $oldSessionID = $this->userdata['session_id'];
+        $newSessionID = $this->generateHash();
+
+        $this->userdata['session_id'] = $newSessionID;
+        $this->userdata['last_activity'] = $this->now;
+
+        $cookieData = null;
+
+        // update the DB if needed
+        if ($this->sess_use_database === true) {
+            // set cookie explicitly to only have our session data
+            $cookieData = array();
+            foreach (array('session_id', 'user_id', 'ip_address', 'user_agent', 'last_activity') as $val) {
+                $cookieData[$val] = $this->userdata[$val];
+            }
+
+            $this->CI->db->update($this->sess_table_name, array('last_activity' => $this->now, 'user_id' => $this->userdata['user_id'], 'session_id' => $newSessionID), array('session_id' => $oldSessionID));
+
+            // update users table if user is logged in
+            if (array_key_exists('user_id', $this->userdata) && $this->userdata['user_id'] > 0) {
+                $this->CI->db->update('users', array('last_activity' => $this->now), array('id' => $this->userdata['user_id']));
+            }
+        }
+
+        // write the cookie
+        $this->_set_cookie($cookieData);
+    }
+}
+
+/* End of file MY_Session.php */
+/* Location: ./application/libraries/MY_Session.php */