I suppose cryptography plays a role in DRM, yes.. But this particular problem with the DRM was an oversight that got corrected. I personally don't think DRM stops piracy. It's just a waste of time and resources but you can't convince bureaucratic pinheads.. I mean, to cite an actual source, Valve themselves noted that one of their best paying customers were Eastern Europe which is interesting due to the high amounts of piracy in that region statistically speaking. Sorry I'm probably driving this topic off-topic. ;p