Is there any plugin where I can protect against unauthorized copy?
a function that gets the unique CPU ID ??

Well, I remember George did something like that in one of the AUMs where the program checked the ID of an optical drive to see if it was the intended recipient. But that being said, most indie developers shouldn't get themselves worked up over piracy prevention because it's not going to work very well anyways; even the big publishers can't prevent people from pirating their games and software. Save yourself some effort and put it into a making the next great game. Goodluck!

Protecting your game against piracy is hard. The plugin is the first thing I would notice in the folder and load up in olly. To find the check now, packed or not, is really easy. Also changing the MAC address, the volume ID and windows key is very easy. The processor ID is not 100% unique but hard to change.

make it free and open source

or require internet connection to sign in, if you want to maintain a server.

Even with a server you cant be sure
YOu can fake server callbacks etc. Take a look @ Fiddler

yes, but probably a little indie game won't be examined by a hacker team, so imo it is enough to protect only agains copying and running it on any machine easily.

No, a static key gives no security.


It depends on the algorithm how the always changing key is evaluated.


A monthly patch should change the whole logic.

Maybe someone should provide such a "webservice"

I think about
ThiApp + online verification