Yuzu, a popular multi platform Nintendo Switch emulator (previously, here) is the target of a lawsuit from Nintendo
Nintendo argued that Yuzu executes codes that “defeat” Nintendo’s security measures, including decryption using “an illegally-obtained copy of prod.keys.”
“In other words, without Yuzu’s decryption of Nintendo’s encryption, unauthorized copies of games could not be played on PCs or Android devices,” Nintendo wrote in the lawsuit.
Nintendo has a long history of filing lawsuits against emulators, ROM hosting, etc, but it’s unclear to me how this could play out. One thing is for sure that a ruling against the makers of Yuzu could have a tremendous chilling effect on emulators in the future.
I’m no legalmancer; but it seems like the (Nintendo-admitted) reliance on keying material that you have to obtain by other means would be a major point in favor of the legality of the emulator.
If something can only ‘break’ encryption when you supply it with somehow-obtained decryption keys from other sources it’s not a circumvention tool; it’s just an interoperable implementation of a decryption library.
Nintendo’s claim seems especially bold given the largely failed attempts to restrict access to DVD CSS or HD-DVD/Blu-ray AACS implementations that don’t actually include the required decryption keys.
If Yuzu were distributing the keys that would seem like pretty straightforward massive trouble; but they specifically avoided doing that; so going after them would amount to claiming that any even slightly eccentric encryption scheme(even in minor details like required formatting and padding, never mind algorithm) is an ‘technological protection measure’ that ‘effectively controls access to a work’.
Claiming that the obscurity of the system, in absence of the key, is part of the protection seems like it would both be broadly chilling and contrary to good advice going back to the good Mr. Kerchoffs in the late 19th century.
None of the above is intended to suggest a belief that Nintendo won’t be able to grind them into the ground regardless of merit; but it seems like a claim that’s the bad combination of shaky and sweeping.
