Question

I want to secure some applications for some people without teaching them how to add an encryption or authentication, so I thought about mocking up a simple application that launches another application if some password or authentication function returns true. How would I wrap the application so that only the launcher would be able to access the file?

Answer 1

If the wrapped (protected) application is managed, you can embed it as an encrypted byte array, then call Assembly.Load(rawBytes) and use reflection to start the application.
(The application should agree to expose some static method or attribute that launches itself, which you can call using reflection)

Note that you’ll still be vulnerable to Reflector, unless you get the decryption key from a web service. (In which case you’ll be vulnerable to a combination of Reflector, Fiddler, and a valid password)