public static string DecryptDES(string Text, string sKey) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); des.Mode = CipherMode.ECB; des.Padding = PaddingMode.PKCS7; int len; len = Text.Length / 2; byte[] inputByteArray = new byte[len]; int x, i; for (x = 0; x < len; x++) { i = Convert.ToInt32(Text.Substring(x * 2, 2), 16); inputByteArray[x] = (byte)i; } des.Key = Encoding.UTF8.GetBytes(sKey); des.IV = Encoding.UTF8.GetBytes(sKey); System.IO.MemoryStream ms = new System.IO.MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); return Encoding.UTF8.GetString(ms.ToArray()); }