I am a programmer. I have about 5 years experience of programming in different kind of languages. I was concerning about my code speed, about optimizing the memory that uses my code, and about good coding style and so on. But have never thought how secure my code is. So I have disassembled my code to see what can do a hacker. Would it be easy to crack my code? And I saw that it is! It is very easy, because I was storing
So if someone has the minimal knowledge of assembler he/she can just simple dissembler and after 10-20 minutes of debugging my code is cracked!!! Even it could be done by opening the exe with notepad I guess! :-)
So what I am asking are the following:
First thing you must realize is that you'll never prevent a determined reverser from cracking any protection schemes because anything that the code can do, the reverser will eventually find out how to replicate it. The only way you can achieve any sort of reliable protection is to have the shipped program be nothing more than a dumb client and have the brunt of the software on some server the reverser has no access to.
With that out of the way, you can certainly make it harder for a would be reverser to break your protections. Obfuscation is the sort of first step in achieving this. I have no experience using obfuscators but I'm sure you can find some suggestions for some on SO. Also if you're using a lower level language like C/C++, simply compiling the code with full optimization and stripping all debugging symbols gets you a decent amount of obfuscation.
I read this article a few years ago, but I still think it's techniques hold up today. It's one of the developers of a video game called Spyro talking about the set of techniques they used to prevent piracy. They claim it wasn't until 3 months after the release that a cracked version became available, which is fairly impressive.