using System;

using System.Text;

using System.Security.Cryptography;

using System.Web;

public class Program

{

    private const string _defaultEncryptKey = "cfd57c17-27f0-462e-b8a3-18fe7f26f699";

    public static string Decrypt(string Text, string sKey)

    {

        DESCryptoServiceProvider des = new DESCryptoServiceProvider();

​

        byte[] inputByteArray = Convert.FromBase64String(Text);

        des.Key = UTF8Encoding.UTF8.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

        des.IV = UTF8Encoding.UTF8.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));

        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());

    }

    public static void Main()

    {

        string data = "aY0+Mxw+tqWivNQ5ZVfOzpCPc9k9DyDicEkKBzrUZZBf1LtBTZGnSqwWHKwhTS3wMpSl0I8WzL5P9XXm7gjbTLgR7V/B+W0JUjsVE6C8mRivBgBIG978mnj/q2kYWAUP";

        Console.WriteLine(Decrypt(data, _defaultEncryptKey));

    }

}