Re: time-based beta termination system
Re: time-based beta termination system
- Subject: Re: time-based beta termination system
- From: "M. Uli Kusterer" <email@hidden>
- Date: Thu, 24 Jul 2003 06:54:56 +0200
At 17:26 Uhr -0700 23.07.2003, Francisco Tolmasky wrote:
Anybody know a good reliable way to make betas terminate/stop
working after x amount of days or after some date? I'd like
something more reliable than just checking the date and thus not
working if someone sets their clocks backwards.
I don't think there's a real way around that. You could of course
save the last date your app was run somewhere (invisible Prefs file?)
and refuse to launch if the current date is before that (but don't
say "you're trying to hack me!" to the user ... that'll only invite
the hackers to try harder -- better just show the same "expired"
message).
Another common approach is to combine the expiration date (say, 30
days) with a limit on how often the app can be run (say, 30 times).
That way, if a user sets back the clock, they still only get 30 days'
worth of usage. Of course, that's only until they find the file where
your app saves that info, so better make it several files in
different locations, with checksums and some redundancy ...
But don't get too fancy, or it will develop bugs and cause honest
users problems. And it's not worth that much effort. A seasoned
cracker can pretty much circumvent any copy-protection you dream up
by liberally adding a few no-ops to the code instead of your
registration checks.
--
Cheers,
M. Uli Kusterer
------------------------------------------------------------
"The Witnesses of TeachText are everywhere..."
http://www.zathras.de
_______________________________________________
cocoa-dev mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/cocoa-dev
Do not post admin requests to the list. They will be ignored.