using System;

using System.Security.Cryptography;

using System.Linq;

using System.IO;

using System.Text;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(Util.Encrypt("text to encrypt")[0]);

    }

}

​

public static class Util

{

    public static byte[] StringToByteArray(string hex)

    {

        return Enumerable.Range(0, hex.Length)

                             .Where(x => x % 2 == 0)

                             .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))

                             .ToArray();

    }

​

    private static readonly byte[] KEY = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 };

    private static readonly byte[] IV = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

​

    public static byte[] Encrypt(string original)

    {

        byte[] encrypted;

        using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())

        {

            aesAlg.Padding = PaddingMode.Zeros;

            aesAlg.Mode = CipherMode.ECB;

            aesAlg.KeySize = 256;

​

            // Create the streams used for encryption.

            using (ICryptoTransform encryptor = aesAlg.CreateEncryptor(KEY, IV))

            using (MemoryStream msEncrypt = new MemoryStream())

            using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))

            {

                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))

                {

                    //Write all data to the stream.

                    //var bytes = Encoding.ASCII.GetBytes(original);

                    swEncrypt.Write(original);

                }

                encrypted = msEncrypt.ToArray();

            }

        }

        return encrypted;

    }

}