AES string encryption/decryption characters are spaced out

Question

I'm encrypting and then decrypting a string using AES. But my output looks like this:

Original text >> HI WORLD  
Decrypted text >> H I   W O R L D

I have tried a lot of code but I have not found the problem.

Where is the problem here?

class Program
{
    public static void Main(string[] args)
    {
        byte[] aesKey = Cryptography.GenerateAes128Key();
        Console.WriteLine("AES key >> " + aesKey.Length);
        string originalText = "HI WORLD";
        byte[] myMess = ASCIIEncoding.Unicode.GetBytes(originalText);
        Console.WriteLine("Original text >> " + ASCIIEncoding.Unicode.GetString(myMess));
        byte[] myEcnryptedMess = Cryptography.Encrypt(myMess, aesKey);
        Console.WriteLine("Encrypted text >> " + ASCIIEncoding.Unicode.GetString(myEcnryptedMess));
        Console.WriteLine("Decrypted text >> " + Cryptography.Decrypt(myEcnryptedMess, aesKey));
        Console.WriteLine("Press any key to continue . . . ");
        Console.ReadKey(true);
    }

    public static byte[] Encrypt(byte[] plainTextBytes, byte[] Key)
    {
        byte[] iv = new byte[Key.Length];
        Aes myAes = Aes.Create();
        ICryptoTransform encryptor = myAes.CreateEncryptor(Key, iv);
        MemoryStream memoryStream = new MemoryStream();
        CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
        cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
        cryptoStream.FlushFinalBlock();
        byte[] cipherTextBytes = memoryStream.ToArray();
        // Close both streams.
        memoryStream.Close();
        cryptoStream.Close();
        return cipherTextBytes;
    }

    public static string Decrypt(byte[] cipherTextBytes, byte[] Key)
    {
        byte[] iv = new byte[Key.Length];
        Aes myAes = Aes.Create();
        ICryptoTransform decryptor = myAes.CreateDecryptor(Key, iv);
        MemoryStream  memoryStream = new MemoryStream(cipherTextBytes);
        CryptoStream  cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
        byte[] plainTextBytes = new byte[cipherTextBytes.Length];
        // Start decrypting.
        int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
        // Close both streams.
        memoryStream.Close();
        cryptoStream.Close();
        // Convert decrypted data into a string.
        // Let us assume that the original plaintext string was UTF8-encoded.
        string plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
        // Return decrypted string.
        return plainText;
    }
}

Answer 1

You are using different Encoding to GetBytes and GetString:

ASCIIEncoding.Unicode.GetBytes(originalText);

and then

Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount)

Try to use same one for both operations.

Kris

Answer 2

You are making a mess with your string encodings. ASCIIEncoding.Unicode is, basically, nonsense. (Actually, it is just the same as Encoding.Unicode , but written in a misleading way.)

Which encoding do you want to use? UTF-16, UTF-8, or ASCII? According to the choice, use either Encoding.Unicode , Encoding.UTF8 , or Encoding.ASCII , and stick to it. I would presume UTF-8 is the best choice, therefore, use this:

// ...
string originalText = "HI WORLD";
byte[] myMess = Encoding.UTF8.GetBytes(originalText);
Console.WriteLine("Original text >> " + Encoding.UTF8.GetString(myMess));
byte[] myEcnryptedMess = Cryptography.Encrypt(myMess, aesKey);
Console.WriteLine("Encrypted text >> " + Encoding.UTF8.GetString(myEcnryptedMess));
Console.WriteLine("Decrypted text >> " + Cryptography.Decrypt(myEcnryptedMess, aesKey));