08-18-2009 06:03 PM
I'm looking for imformation on implementing a licensing system based on RPN strings.
How is RPN best used to generate a license key from the deviceID, and is there a convenient class or code excerpt anyone would like to share or link to that does the calculation inside the app?
Would the app be easy to crack now that .cod files can be decompiled? The app needs to calculate the license key from the deviceID and then compare with what the user entered, but that means a hacker can use that same code to make a key generator, or just patch the comparison and distribute a cracked version?
Is there a way to compute in reverse from license key to deviceID, and then compare the real with calculated deviceID instead? Wouldn't that make it at least slightly more difficult to make a key generator?
Thanks for any info from people experienced with this...
02-28-2010 07:42 PM
You might checkout the licmax service (http://www.licmax.com) and the explaination of how they do hashing for disconnected/offline license verification. Hashed license keys seemed to us to be just as good as RPN. Their docs explain how it works: http://www.licmax.com/developersTab.html