Encrypt .NET assembly to string

encrypt.cs

String path = args[0];
key = getRandomKey();
String filename = Path.GetFileNameWithoutExtension(path).ToString();
String obfuscatedBin = obfuscateBinary(path);

private String obfuscateBinary(String file) {
    byte[] assemblyBytes = fileToByteArray(@file);
    byte[] encryptedAssembly = encrypt(assemblyBytes, key);
    return System.Convert.ToBase64String(encryptedAssembly);
}