const char key[] = {'x41', 'x41', 'x37', 'x44',
                        'x44', 'x34', 'x30', 'x33',
                        'x30', 'x35', 'x39', 'x4e',
                        'x36', 'x37', 'x30', 'x38'};
    AESstreamState encrypt_state; //built in Dynamic C type
    char init_vector[16];
    int i;
    int bufLength;

    sprintf(Buf, "%s", "testabc");
    bufLength = strlen(Buf);

    for (i = 0; i < 16; i++)
        init_vector[i] = rand() % 255;

    printf("Key: ");
    for (i = 0; i < sizeof(key); i++)
        printf("%d ", key[i]);
    printf("n");

    AESinitStream(&encrypt_state, key, init_vector);  //built in Dynamic C function
    AESencryptStream(&encrypt_state, Buf, bufLength); //built in Dynamic C function

    printf("Data: ");
    for (i = 0; i < strlen(Buf); i++)
        printf("%d ", Buf[i]);
    printf("n");

    //set first byte to something that lets the server know it's encrypted
    //set 2nd through 16th byte to the IV (initialization vector) so every message will be different even if they have the same contents
    for (i = bufLength-1; i >= 0; i--)
        Buf[i+17] = Buf[i];
    Buf[0] = 237; //φ

    printf("IV: ");
    for (i = 1; i < 17; i++)
    {
        printf("%d ", init_vector[i-1]);
        Buf[i] = init_vector[i-1];
    }
    printf("n");

private string DecryptAES(byte[] cipherText, byte[] IV)
    {
        byte[] key = {
            0x41, 0x41, 0x37, 0x44,
            0x44, 0x34, 0x30, 0x33,
            0x30, 0x35, 0x39, 0x4e,
            0x36, 0x37, 0x30, 0x38
        };

        // Check arguments.
        if (cipherText == null || cipherText.Length <= 0)
        {
            throw new ArgumentNullException("cipherText");
        }
        else if (IV == null || IV.Length <= 0 || IV.Length != 16)
        {
            throw new ArgumentNullException("IV");
        }

        Console.Write("Key: ");
        for (int i = 0; i < key.Length; i++)
            Console.Write("{0} ", key[i]);
        Console.WriteLine();

        Console.Write("Data: ");
        for (int i = 0; i < cipherText.Length; i++)
            Console.Write("{0} ", cipherText[i]);
        Console.WriteLine();

        Console.Write("IV: ");
        for (int i = 0; i < IV.Length; i++)
            Console.Write("{0} ", IV[i]);
        Console.WriteLine();

        // Create an RijndaelManaged object
        // with the specified key and IV.
        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Mode = CipherMode.CFB;
            rijAlg.FeedbackSize = 8;
            rijAlg.BlockSize = 128;
            rijAlg.Padding = PaddingMode.None;

            rijAlg.Key = key;
            rijAlg.IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

            // Create the streams used for decryption.
            using (System.IO.MemoryStream msDecrypt = new System.IO.MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (System.IO.StreamReader srDecrypt = new System.IO.StreamReader(csDecrypt))
                    {
                        // Read the decrypted bytes from the decrypting stream
                        // and place them in a string.
                        string plaintext = null;

                        plaintext = srDecrypt.ReadToEnd();

                        Console.WriteLine("Decrypted: " + plaintext);

                        return plaintext;
                    }
                }

            }
        }
    }