Copy / Protection Ideas

Hi,

I am working a client-server project, with a server being sold and client distributed for free. I need to somehow protect the server software from being replicated onto others computers. I have already implemented a licensing system, which heavily limits the concurrent connection limit, but the software can still be copied.

Any protection ideas?

Thanks for any help,

Nothing that won't get cracked within about 20 minutes.

Try IDs. On install, an ID is given to the system. If the ID is seen twice at any given moment, ban it. However, this is easily cracked.

Other than giving each CD an explicit ID# at production and then using the above technique, I have nothing.