diff --git a/app/common/utils/SystemAuth.php b/app/common/utils/SystemAuth.php
index cbef538..6977fa8 100644
--- a/app/common/utils/SystemAuth.php
+++ b/app/common/utils/SystemAuth.php
@@ -14,7 +14,7 @@ class SystemAuth
     public static function generateSignature(string $userId, int $timestamp, string $secret): string
     {
         $data = $userId . $timestamp;
-        return hash_hmac('sha256', $data, $secret);
+        return hash_hmac('md5', $data, $secret);
     }
 
     /**