Jose Jimenez said:
Hi Folks I wonder if somebody can help me to copy protect a C program that
runs under ms-dos compilated with djgpp... and gcc
I'm afraid I can't help you locate a copy protection system, because
such a thing does not really exist.
What you are looking for is something to prevent piracy of your
software, and that is nearly impossible in current computing
envionments. Instead, what you can do is make your software useful
only when a relationship exists between the user and your company -
eg. by providing good support, by acting as a service bureaux, or
<insert healthy business practice here>.
Modifying the software to run in an obfuscated fashion, or to require
the attachment of a dongle to the computer only delays the inevitable
- all parts of your code will be unpacked at some stage during it's
execution, and someone with enough time and knowledge will be able to
leverage this fact to steal your program.
I don't think a perfect copy protection exists for any software
environment yet. I am interested in what advances may be made in this
field with the ongoing roll-out of 'trusted computing' initiatives.
Save your time my friend, reinvest it in improving your software and
business model so that piracy isn't a problem. Take a look around you,
there are software systems 1000 times bigger than yours (at a guess)
that don't use copy protection.
Copy protection costs time and money, requires integration, is easily
broken, and is more or less a flawed concept in general.
</opinion>
David.