To Decrypt Eval Key

  /// <summary>
        /// To Decrypt Eval Key
        /// </summary>
        /// <param name="queryString"></param>
        /// <returns></returns>
        public static string DecryptKey(string queryString)
        {
            CryptoServices cryptoServicesObj;
            cryptoServicesObj = new CryptoServices();
            if (!string.IsNullOrEmpty(queryString))
            {
                return cryptoServicesObj.DecryptString(queryString, "56565656");
            }
            else
            {
                return queryString;
            }
        }