Registration Code

[Ryan Ginstrom]

> On Behalf Of Dave Mandelin:
> Second, I hear that in general it is very difficult to make a
> time-limited demo, because the code has to be all there, so all a
> cracker has to do is bypass the "if". It seems that even this method
> won't work for that. Do you know of any way to make time limiting
> secure?

If the application is to be Windows only (and I assume this from statement
about using py2exe), one fairly secure and easy method is to put some
critical functionality into a plain DLL or (compiled) COM module, and use a
commercial software-protection program like Armadillo on that. Armadillo is
much more secure than just about anybody could make on their own, and instead
of wasting time (and probably introducing bugs) implementing it yourself, you
can use that time improving your application. Armadillo handles all sorts of
protection schemes, from time limitations to machine locking and "crippling,"
and combinations thereof. (I have no commercial or other interest in
Armadillo.)

Another tack to take is to maintain content updates on a Website for
download. The Website would check the registration code. This foils most
cracking methods, and even shared codes can be blacklisted when found. Of
course, this only works for certain types of applications, but when it is
possible it has the benefits of not requiring significant changes to your
application, remaining transparent to the user, and most importantly, not
antagonizing legitimate users. And of course, it would enable cross-platform
(commercial) use of your application. A variation of this strategy is the
subscription model.

Regards,
Ryan

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Ryan Ginstrom
http://ginstrom.com