diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 3711b5fdf8d..bde71c2787c 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -6029,7 +6029,7 @@ function get_list_of_currencies() {
  * @todo Finish documenting this function
  */
 function rc4encrypt($data) {
-    $password = 'nfgjeingjk';
+    $password = get_site_identifier();
     return endecrypt($password, $data, '');
 }
 
@@ -6041,7 +6041,7 @@ function rc4encrypt($data) {
  * @todo Finish documenting this function
  */
 function rc4decrypt($data) {
-    $password = 'nfgjeingjk';
+    $password = get_site_identifier();
     return endecrypt($password, $data, 'de');
 }