diff --git a/imagecache.module b/imagecache.module
index e545498..5b05924 100644
--- a/imagecache.module
+++ b/imagecache.module
@@ -400,7 +400,7 @@ function imagecache_create_url($presetname, $filepath, $bypass_browser_cache = F
 function imagecache_style_path_token($presetname, $path) {
   // Drupal 6 may not yet have drupal_get_hash_salt().
   global $db_query;
-  $salt = hash('sha256', serialize($db_query));
+  $salt = sha1(serialize($db_query));
   // Return the first eight characters.
   return substr(_imagecache_hmac_base64($presetname . ':' . $path, drupal_get_private_key() . $salt), 0, 8);
 }
@@ -418,7 +418,7 @@ function _imagecache_hmac_base64($data, $key) {
   $ipad = $ipad ^ $key;
   $opad = $opad ^ $key;
 
-  $hmac = base64_encode(sha1($opad . pack("H*", sha1($ipad . $data))));
+  $hmac = base64_encode(pack("H*", sha1($opad . pack("H*", sha1($ipad . $data)))));
   // Modify the hmac so it's safe to use in URLs.
   return strtr($hmac, array('+' => '-', '/' => '_', '=' => ''));
 }