On Fri, 19 Sep 2008 04:53:43 -0700 (PDT), Tomer <tomerbd1@gmail.com>
wrote, quoted or indirectly quoted someone who said :
Can anyone guide me how can i create a 30 days trial to a software
that is immune to having set the clock back in time?
Icon Lover has a scheme that I wish more would implement.
It gives you a 30 day trial, but does not count days on which you
don't use the program.
1. use an atomic clock to find out the real time. See
http://mindprod.com/products1.html#SETCLOCK
2. give the user N uses of the program, over any length of time. They
would have to find where you hide the count.
3. Have the program send a query to a server on each trial use to see
if it ok to use it. You maintain the data on your server where it is
not discoverable or tamperable.
See http://mindprod.com/jgloss/installer.html
4. Do not provide time-limited or otherwise restricted copies of the software.