Необходимо зашифровать нетекстовый файл( exe, jpg.) - C#

public static void DecryptFile(string sInputFilename, string sOutputFilename, string sKey)
{
    DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
    //A 64 bit key and IV is required for this provider.
    //Set secret key For DES algorithm.
    DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
    //Set initialization vector.
    DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
 
    //Create a file stream to read the encrypted file back.
    FileStream fsread = new FileStream(sInputFilename, FileMode.Open, FileAccess.Read);
 
    //Create a DES decryptor from the DES instance.
    ICryptoTransform desdecrypt = DES.CreateDecryptor();
 
    //Create crypto stream set to read and do a 
    //DES decryption transform on incoming bytes.
    CryptoStream cryptostreamDecr = new CryptoStream(fsread, desdecrypt, CryptoStreamMode.Read);
 
    //Print the contents of the decrypted file.
    StreamWriter fsDecrypted = new StreamWriter(sOutputFilename);
    fsDecrypted.Write(new StreamReader(cryptostreamDecr).ReadToEnd());
    fsDecrypted.Flush();
    fsDecrypted.Close();
}