Daniel Rubin wrote:
>
> Now this is good information. The n times a day idea is a good one. People who
> like the app will want to use it more than n times a day and therefore purchase a
> "full version". Furthermore, it would require no presistant data and would be a
> royal pain in the ... to reinstall it every day. Everyone is happy! Thanks for the
> great idea Roger!
Yes, I agree, however it still needs to be set up so that a simple
edit of the file on disk - a crack - does not disable the feature.
The common "theme" in counter based detection is a compare of
one value with another. By searching for these magic numbers (3 uses,
7 days, whatever) and then looking for compare statements in assember,
a cracker will often noop the operation, or set a loop counter to
compare 0>0 or some such thing.
I like the persistent database based key or crack detection feature
as well.
-Tim
--
Tim Hewitt
Principal Software Engineer
Fairchild Semiconductor
