diff --git a/swarmlab-app/src/run/app.js b/swarmlab-app/src/run/app.js
index 43412e4..3c2538d 100755
--- a/swarmlab-app/src/run/app.js
+++ b/swarmlab-app/src/run/app.js
@@ -427,8 +427,17 @@ cors(corsOptions),  (req, res, next) => {
 //      socket
 // ***************************************************
 
-function getSHA256ofJSON(input){
-  return   require("crypto").createHash("sha256").update(JSON.stringify(input)).digest("hex");
+//function getSHA256ofJSON(input){
+//  return   require("crypto").createHash("sha256").update(JSON.stringify(input)).digest("hex");
+//}
+const getSHA256ofJSON = (data: string, inputEncoding, encoding) => {
+  if (!data) {
+    return '';
+  }
+  inputEncoding = inputEncoding || 'utf-8';
+  encoding = encoding || 'hex';
+  const hash = crypto.createHash('md5');
+  return hash.update(JSON.stringify(data), inputEncoding).digest(encoding);
 }
 
 //var getkey = function getkey(key) {