On Feb 25, 7:58 pm, Streets Of Boston <flyingdutc...@gmail.com> wrote:
> How do you make a time limited trial version, where limiting the time > is fairly fool-proof? How do you know how long the user has your app > installed (including the possibility that the app has been uninstalled > one or more times...)? I go the server-registration route. The app in question already needs net access, and I have a server that it talks to already, so I just created a narrow MySQL table server-side and a simple PHP script to interface with it. Essentially, I store the IMEI, app version number, and the date of first use, and use that to validate the trial period. My original implementation didn't include version number, but I soon realized that it was desirable to let people re-trial when I released a new version. I've also decided not to bother with any encryption on the trial period validation. I recognize that my approach is vulnerable to MITM attacks, but it's sufficient to keep honest people honest; if someone's going to that much trouble to screw me out of $2, there's not much hope, is there? Besides, the whole Android-market piracy aspect is a much bigger security hole. It's far more likely that someone will simply download my license app from a warez site than bother with cracking my validation routine. String -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
