> Or they add something that detects your legitimate disc and lets you play it. I don't > believe the readable portion in Xbox discs is the same across all discs, so I think > this could be a plausible workaround. I admit I am completely ignorant about Xbox > disc layout though.
The readable portion was a stock file applied by the custom disc mastering software, which means at best it might be different between SDK versions. It definitely can't be used to identify specific discs.