In my opinion, the key problem you'll face is not with your registration algorithm and level (or lack) of obfuscation.
Rather, it's this: At some point in your code it comes down to simple binary decision - to run, or to exit. Hacking your system only requires finding and tweaking this decision point.
Everything else - obfuscation, strong signing, tamper detection - is oriented to make this more difficult, but it can't make it that much harder.
