diff --git a/LaunchServer/source/auth/provider/MineSocialAuthProvider.java b/LaunchServer/source/auth/provider/MineSocialAuthProvider.java
index ef8aacc..d4d82ab 100644
--- a/LaunchServer/source/auth/provider/MineSocialAuthProvider.java
+++ b/LaunchServer/source/auth/provider/MineSocialAuthProvider.java
@@ -91,11 +91,10 @@
         {
             MessageDigest md = MessageDigest.getInstance("SHA-1");
             byte[] array = md.digest(password.getBytes());
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
 
-            for (int i = 0; i < array.length; ++i)
-            {
-                sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1,3));
+            for (byte b : array) {
+                sb.append(Integer.toHexString((b & 0xFF) | 0x100), 1, 3);
             }
             return sb.toString();
         }