public string GenerateSignature(string key, string data)
        {
            Func <string, byte[]> getBytes = Encoding.UTF8.GetBytes;


            var encoder = new /*HMACSHA256*/ HMACSHA1(getBytes(key));

            var hash = encoder.ComputeHash(
                getBytes(data)
                );

            var sign = Convert.ToBase64String(hash);

            //Console.WriteLine(data + " : " + sign);

            return(sign);
        }
		public string GenerateSignature(string key, string data)
		{
			Func<string, byte[]> getBytes = Encoding.UTF8.GetBytes;


			var encoder = new /*HMACSHA256*/HMACSHA1(getBytes(key));

			var hash = encoder.ComputeHash(
				getBytes(data)
				);

			var sign = Convert.ToBase64String(hash);

			//Console.WriteLine(data + " : " + sign);

			return sign;

		}