I have just made a software with a serial number protection: it pops a menu up every minute until the user do not insert a code. The protection works this way:
The program gets some parameters from the registy like username, license nr. etc.
Then it converts these strings in numbers and put them togheter; it does some math operations and gives back a numeric code (that is, this way, machine-dependent).
Then the user has to send me this code, i apply some math operations on this and give it back to the user who has to insert it in a special field. It will be then stored in the registry. The key is veryfied every time the program starts.
Is this a good protection, in your opinion?
Thanks