I've made a program that I need to license before selling it to customers. Since I'm not sure, that it will gain me at least the cost of commercial licensing software, I would not like to buy one.
So I'm looking for advice on how to implement licensing feature with following logic:
- All license keys are validated on server side each time application starts (no licensing info is stored at userside except the license number).
- There is only one application running with one license key at the same time.
What I do not know is how to protect my program from simple decompiling/disassembling and just removing a call to check license? Or making own server that will make a response true on each license? How does such security normally made?
I've searched for free SDKs or something like that, but could not find anything. I'll be very thankful for your help!
P.S: I do not aspire to make the system "indestructible", but I would like to receive the protection that is more expensive to crack than paying $5.10 for a copy of the program.
P.P.S: Sorry for my bad english.