Re: time-based beta termination system
Re: time-based beta termination system
- Subject: Re: time-based beta termination system
- From: Tim Ramsey <email@hidden>
- Date: Thu, 24 Jul 2003 13:11:26 -0500
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
In support of the number of runs method instead of the expiration
date method - it keeps people like me from cursing you and not buying
your product. I frequently download a shareware application because
it does a function I occasionally need or because it might do
something better than my current tool and I want to test it. I buy
the ones I find myself using. Frequently, I will download an
application, bring it up for an initial look and hang on to it if it
passes that test. Then I get busy on something where I have no use
for that product. Two or three months later, I have a need for that
type of application and try the new product to see if it works well
for me in practice. If I find the 30 day death has happened, I throw
it away and your chance to sell it to me has vanished because I have
to be really desperate to buy something that I have not tested. I'll
keep using what I have been using, look for a different application
or roll my own depending on the task.
--
Tim
"To invent, you need a good imagination and a pile of junk."
--Thomas Edison
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