filed under CodingTips

Here is an active discussion at CocoaDev on the pros and cons of various software registration methods. There is a particularly good explanation over in the MacroMates archive of how to use OpenSSL to generate encrypted license keys.

Some conclusions after the jump.

The bottom line is that all such licensing systems can be cracked, given sufficient effort. The goal is to make it not worth the effort to crack your app and distribute either a cracked version or a valid license key before you bring out your latest and greatest version (assuming, of course, that license keys are invalidated with each new version).

Another important point for Mac OS X developers is that any application code related to licensing should be statically linked (so a C static lib, rather than an Obj-C framework). Otherwise your carefully crafted licensing scheme can be swapped out fairly trivially at run-time.

License Key Generation [CocoaDev]