> I'd like to hear other people's experience on the subject. Namely Aaron
> Ardiri's who, I believe, started to write one of these self-modifying
> code copy protection mechanisms some time ago. Everytime someone raises
> this don't-leave-data-behind war, there's a lot of vague discussion
> where I'd like to see some good ideas pop up.
:)) the crackers are *very* good.. however, i have a surprise
for my next release :)) i use a checksum to decrypt my regcode
algorithm routine..
they patch the program - the checksum is invalid and hence the
routine does not decrypt properly.. however, they we smart to
do this.. they hardwared the check sum in the program right
before the call :)) i did not expect that... but i learnt a
lesson from it.. :))
my next version extends the principle one step further..
instead of a static "checksum".. i will have a dynamic
one.. using the code that "performs" the checksum as my
data for generating the new key :)
kindof like weaving in and out of the code you are executing
:)) this will make them happy :))
also.. as a word of advice.. a keygen routine is actually
pretty good for a random function :)) incorporate it into
your program :)) this means they cannot just eliminate it
:))
but seriously.. if you dont have time to do this.. dont
bother.. i do it for fun.. i like to see how far these guys will
go :)) i dont believe it really affects my sales :))
they crack ->> the harder the better they feel
i protect ->> the longer they take.. the better i feel :)
a good encryption algorithm is something like RC-4 :) if you
want to look into it :))
cheers.
az.
--
Aaron Ardiri
Java Certified Programmer http://www.hig.se/~ardiri/
University-College i G�vle mailto:[EMAIL PROTECTED]
SE 801 76 G�vle SWEDEN
Tel: +46 26 64 87 38 Fax: +46 26 64 87 88
Mob: +46 70 656 1143 A/H: +46 26 10 16 11
