DMCA Section 1201 is your answer. Those keys are primarily used for circumventing “technological protection measures” on software. That’s not legal even for otherwise legal uses which is why the Section is morally awful. What you do could be completely legal otherwise, but if it involves circumventing these “TPMs” of which encryption keys are an important part of, you’re screwed.
An emulator, meanwhile, only mimics hardware which is considered legal. An example: It is completely legal to implement the DVD specification; but brute-forcing the keys to decrypt DVDs because you don’t have a license is not.
The same applies to AACS, which protects Blu-ray Discs. It’s actually published publicly - you can just go download the spec for that copy protection right now. But getting a legal, unique device key will require contracts.
Stupid? Yes, but that’s where the law is drawn right now.
An emulator, meanwhile, only mimics hardware which is considered legal. An example: It is completely legal to implement the DVD specification; but brute-forcing the keys to decrypt DVDs because you don’t have a license is not.
The same applies to AACS, which protects Blu-ray Discs. It’s actually published publicly - you can just go download the spec for that copy protection right now. But getting a legal, unique device key will require contracts.
Stupid? Yes, but that’s where the law is drawn right now.