Update README.md

README.md

@@ -8,7 +8,8 @@ This is a small description of how the chain works and how data is being formatt
   "key": "public key of the contract",
   "id": "transaction id",
   "timestamp": "unix timestamp of transaction creation",
-  "data": "encrypted string of contract"
+  "data": "encrypted string of contract",
+  "encrypted key":"encrypted semmetric key"
 }
 ```