private static byte[] encStep(byte[] data, DESCryptoServiceProvider DES1,
        DESCryptoServiceProvider DES2, DESCryptoServiceProvider DES3, int from, int to)
    {
        ICryptoTransform eTransform = DES1.CreateEncryptor();
        byte[] enc1 = eTransform.TransformFinalBlock(data, from, to);
        Console.WriteLine(enc1.Length);

        eTransform = DES2.CreateEncryptor();
        byte[] enc2 = eTransform.TransformFinalBlock(enc1, from, to);
        Console.WriteLine(enc2.Length);

        eTransform = DES3.CreateEncryptor();
        byte[] enc3 = eTransform.TransformFinalBlock(enc2, from, to);
        Console.WriteLine(enc3.Length);

        return enc3;
    }

    private static void OCBC(byte[] Data, string encFile, string decFile)
    {
        try
        {
            //_______________________ENCRYPT_____________________________
            DESCryptoServiceProvider DES1 = new DESCryptoServiceProvider();
            DES1.Mode = CipherMode.ECB;
            DESCryptoServiceProvider DES2 = new DESCryptoServiceProvider();
            DES2.Mode = CipherMode.CBC;
            DES2.Padding = PaddingMode.None;
            DESCryptoServiceProvider DES3 = new DESCryptoServiceProvider();
            DES3.Mode = CipherMode.CBC;
            DES3.Padding = PaddingMode.None;

            int temp;
            if (Data.Length%64 != 0)
                temp = (Data.Length/64 + 1) * 64 + 8;
            else temp = Data.Length + 8;
            byte[] encrypted;

            int i = 0;
            bool flag = true;
            while (i < Data.Length && flag)
            {
                encrypted = encStep(Data, DES1, DES2, DES3, i, i + blockSize);
                i += blockSize;
                //Console.WriteLine(encrypted.Length);
            }


            //File.WriteAllBytes(encFile, enc3);

            //______________________DECRYPT________________
            /*ICryptoTransform dTransform = DES3.CreateDecryptor();
            byte[] dec3 = dTransform.TransformFinalBlock(enc3, 0, enc3.Length);

            dTransform = DES2.CreateDecryptor();
            byte[] dec2 = dTransform.TransformFinalBlock(dec3, 0, dec3.Length);

            dTransform = DES1.CreateDecryptor();
            byte[] dec1 = dTransform.TransformFinalBlock(dec2, 0, dec2.Length);

            File.WriteAllBytes(decFile, dec1);*/

            Console.WriteLine("OCBC done");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }