private DESCryptoServiceProvider crDES = new DESCryptoServiceProvider();
    crDES.Mode = CipherMode.CBC;
    crDES.Padding = PaddingMode.PKCS7;
    crDES.GenerateIV();
    crDES.GenerateKey();

 
 
    private byte[] DoDESCrypt(byte[] Data, bool Encrypt ) 
    { 
      if( Data == null )
        throw new ArgumentNullException("Data for encryption should not be" & _
          "null!");
      byte[] cryptData = null; 
      using( MemoryStream ms = new MemoryStream() )
      {
        ICryptoTransform Trans = null;
        if( Encrypt )
          Trans = crDES.CreateEncryptor( crDES.Key, crDES.IV );
        else
          Trans = crDES.CreateDecryptor( crDES.Key, crDES.IV );
 
        using( CryptoStream cs = new CryptoStream(ms, Trans, _
          CryptoStreamMode.Write) )
        {
          cs.Write(Data, 0, Data.Length); 
          cs.Close(); 
          cryptData = ms.ToArray(); 
        }
      }
      return cryptData; 
    }