Making my EXE 'save' (from Cheats and hacks...)

[M109uk]

With my project im using MD5 digests to check if any of the files have been modified.. it has its problems, mostly being that i cant store the MD5 digest in the application because of course it changes everytime i build the application.

To make it harder to hack, i have the verifying functions in an inc file and include it in to the create events of the most classes and the a lot of other events during the creation, initialization and rendering stages of the game..

e.g.
[/pascal]constructor TuPlayers.Create;
{$include uMD5DigestVerify.inc}
begin
If DoMD5Verify(Application.ExeName) Then
Legal else
Hacked;

// do some stuff
end;
[/pascal]

It probably isnt the greatest of ideas..

--

Im adding some other ideas from what i seen in the spyro topic

[Firlefanz]

Hello,

I made some 'random' licence methods that don't do much at all, some additional variables to make score, energy and credits harder to find and so on.

I now downloaded UPX and upxed my Exe.
It was 1037 kbyte before and now it is only 373 kbyte, very nice

A first small test run showed no differences.

First of all can I be sure that everything still works or do I have to test everything again?

Do I lose frames because it is packed? I saw no difference...

Last point: I heard it can be unpacked again, any way to make it impossible? Changing the header somebody said? How?

Thanks a lot!

Firle

[K4Z]

UPX really only compresses exe's, you shouldn't rely on it to protect your exe's alone. There are some programs that can encrypt your exe, but just like UPX has unpackers, most have decrypters.

When you run a UPX compressed exe, it automaticaly decompresses the program to it's original state, so there's no real loss of performance while running.

Yes, you should test everything, not only test that the protection hasn't caused bugs in your code, but also the protection itself. Grab a memory editor and/or a hex editor and just tinker around, see if the security actually does anything to hinder cracking.

Good Luck!