public static string DESEncrypt( string originalString )
        {
            DESCryptoServiceProvider key = new DESCryptoServiceProvider();
            Encoding enc = Encoding.Default;

            MemoryStream ms = new MemoryStream();
            CryptoStream encStream = new CryptoStream( ms , key.CreateEncryptor(bytes,bytes) , CryptoStreamMode.Write );
            StreamWriter sw = new StreamWriter( encStream );
            sw.WriteLine( originalString );
            sw.Close();
            encStream.Close();
            byte[] buffer = ms.ToArray();
            ms.Close();

            return enc.GetString( buffer );
        }