Hey I'm trying to add a little copy-protection check to my game... The CD serial number after burning does not seem to be related to the serial number printed on the middle of the blank CD-R. Obviously if I am to tie my game to a CD's serial number I need to know it prior to burning. Can you help here? Thanks a lot! (and btw before someone mentions, I won't check the CD on every startup because that would get annoying, just every month or something)

If you have control of the burning, then you can put a separate file (that you know the structure of) on each copy you burn. This contains your own serial number.

Another way is to require internet activation every so often. Put a sticker on the CD case with a unique number, and have a web-based database with all these numbers in it. When someone registers a specific number (given an e-mail address, say), you mark this as "used" and won't allow other e-mail addresses to register that same number in the database. Store the e-mail and the serial number in the registery on the install computer, as well.

On launch, connect to your server and check that the serial number is "allowed." If you can't connect, perhaps allow for a grace period of a week or two without connection. Also don't allow the IP address to change more than, say, once an hour -- this will prevent sharing of the serial number/email address pair.

In the end, copy protection can be broken by a determined attacker, so any protection you design should be aimed towards keeping honest people honest, and intrude as little as possible.

Thanks for the quick reply [smile]

Quote:Original post by hplus0603
If you have control of the burning, then you can put a separate file (that you know the structure of) on each copy you burn. This contains your own serial number.

I'm really just going to sell at school so I do control the burning, but the trouble with that method is that the file would be copied CD to CD with standard CD burning software that you find on any computer.
Instead I'm wanting to tie a particular build of the game to the actual CD.

Quote:
Another way is to require internet activation every so often. Put a sticker on the CD case with a unique number, and have a web-based database with all these numbers in it. When someone registers a specific number (given an e-mail address, say), you mark this as "used" and won't allow other e-mail addresses to register that same number in the database. Store the e-mail and the serial number in the registery on the install computer, as well.

On launch, connect to your server and check that the serial number is "allowed." If you can't connect, perhaps allow for a grace period of a week or two without connection. Also don't allow the IP address to change more than, say, once an hour -- this will prevent sharing of the serial number/email address pair.

That's a clever solution! However I ruled out registration as I don't want to require internet access neither am I going to be able to have a server.

Quote:
In the end, copy protection can be broken by a determined attacker, so any protection you design should be aimed towards keeping honest people honest, and intrude as little as possible.

Yep, that's ever so true. I'm really just trying to stop the amateurs. I know people can get straight disc to disc copiers with no copy protection but I don't think my game would be good enough to attract pirates that determined! [grin]

Thanks!

If you're just going to be selling it at school, I would create a simple algorithm to check if the user-provided key matches a given decryption or whatever. The problem with this is that someone can create a key-generator (which happens a lot with big-brand games nowadays), but at school I don't think anyone is going to be that determined to mass distribute your game, not unless the game is like, really, really good, in which case you should probably contact a publisher to distribute your game instead...

Hey, thanks Omega

However, the scenario that I'm trying to address is where some dishonest person, you only need one, copies the CD and passes copies on. I can see people accepting those copies to 'just try it out' with good intentions, but because people are lazy and 'hey i've got the game and it works' they probably won't bother to buy the game once they have it. If there was a key of course that would be just too easy to pass on.

That's why I think the only alternative to online registration is to tie each burn of the game to the physical media.

Cheers (and rates)