[busterarm]

I don't know if any of the web sites are still up, but King of Fighters 2000 was the first arcade game that I remember with both fairly difficult ROM encryption and a public, documented effort to crack it. The cart was being dumped by two groups, one based in Italy and one in Taiwan, that posted loads of pictures and a detailed technical explanation of what they had to do. The project deserved a book like Hacking The Xbox.

Worth a read if you can still find any of it. It also kind of marks the end of an era in arcade hardware -- that was the last major effort of a manufacturer to really lock down a game through this means; afterwards everyone switched to the more advanced disc-based systems that were hard/impossible to emulate instead of being hard to decrypt.