Hi

I'm trying to make the following solution.
(1) the person would email me their unique Hardware ID.

(2) I would return a matching unlock key, which the person would put in a text file in their directory. The app would pick up the unlock key and go through some simple algorithm to determine if it is complementary to the hardware ID.

I was wondering if someone could give some advice.

(note:
i don't want a for-pat commercial application. I already spent about 300 dollars on EXECryptor and received absolutely no tech support. EXECryptor was a complete waste of money.

I also realize such a solution would be crackable but I just want something very simple. I'm just curious about hearing some ideas. )

I was also wondering if there was some simple open source library I could put in to do this.
I realize also on the simplest level I could make my unlocking key simply every 3 characters of the hardware id but some could easily pick this up.

Thanks
Stephen