Is there any facility to protect the contents of an APK from user modification?

Question

I was thinking about this earlier and figured I'd ask.

If I made an application that has lots of resources, what would stop someone from extracting and adding/modifying the resources I ship with it?

Does an application that doesn't want its data manipulated have any sort of option to protect itself?

Answer 1

Nothing prevents someone from extracting resources -- there is even an API for that. However, there is no way to modify the contents of an installed APK file, because that file is digitally signed.

Somebody with root access could obtain the APK file, mess with its contents, and re-sign it, for their own purposes, at least in theory.