Simple copy protection system.

[Mirage]

I'm looking for a simple copy protection unit. It can be very simple, such as a Name-Serial copy protection system, with a trial period.

Generate a license key from name's hash. When user enters his name and key, generate a hash from name, restore hash from key and compare.
Thus the key generation algo is not present in program's code at all, so extract a keygen from it wouldn't be easy.
To implement a trial period you can encrypt current date and write somewhere to hdd/registry at program's first run. If the record is not present - assume that the trial is over.