DiskGuard cd protection

can try here too.. www.gamecopyworld.com


WBR

Surej

Thank you both but I'm not trying to make a copy of the cd.. In fact I dont have the original cd just this non working copy..
To make things more clear this is what Diskguard is all about:

DiscGuard™ is an anti-piracy system that effects two basic changes to the software package:
* The main executable files on a DiscGuard-protected CD-ROM are encrypted.
* A special digital signature is inscribed onto a pressed CD-ROM, and mapped into a software decryption key. The digital signature is not reproducible by either counterfeiting (re-mastering) or disc burning.

When an authentic disc is used, the signature is present, decryption occurs and the application runs. The user is not even aware that the product is protected. When a copy is used, the signature is not present, no decryption occurs and the application does not run. Instead, a message, a limited demo, a link to an e-commerce web site or a presentation is launched. This transforms every illegal copy into a marketing tool and revenue generator.

So far I've found out the encryption algorithm (Blowfish) and the hash function used (Haval) inside a dll. This dll doesn't export any functions, just two ordinals I don't have of course the decryption key but I do have a working limited editon demo of the executable. Is it possible to find the decryption key simply by comparing the two files?