public String createSignature(String key, String data)
 {
     byte[] keyBytes = System.Text.Encoding.UTF8.GetBytes(key);
     byte[] hashValue;
     using (HMACSHA256 hmac = new HMACSHA256(keyBytes))
     {
         hashValue = hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(data));
     }
     return(EncodingUtil.HexEncode(hashValue));
 }
        public String pbkdf2(String value, String salt, int iterations)
        {
            String hash = EncodingUtil.HexEncode(PBKDF2Sha256GetBytes(
                                                     32,
                                                     System.Text.Encoding.UTF8.GetBytes(value),
                                                     System.Text.Encoding.UTF8.GetBytes(salt),
                                                     iterations));

            return(hash);
        }