If Sony was still in the business, they would offer a certificate renewal for a small fee like the other manufacturers have done.
The root problem is that Sony exited the market and left a lot of cinema owners out to dry with the looming cost of $50,000+ per auditorium for replacement projectors.
You can't build a "time lock" with just encryption primitives. Even if you could build a time lock with just encryption primitives, we don't know when the copyright will expire until the original author has died, since copyright term is life + 70 years.
Someone would have to run a server that specifically chooses to start serving the keys on that date, which is an absurd notion given how absurdly long copyright lasts these days.
If the federal government were interested in passing a law that required this, I'm sure the Library of Congress could run such a server, but no such law exists.
Maybe not through crypto but otherwise perfectly achievable. No reason to achieve this within a file. If you really want to, some fancy solution involving blockchains and smart contracts is probably possible but there is no need.
Require by law all who desire copyright protection to register the work with a governmental agency and place a copy of the work in escrow at an archive as a condition. The archive knows when the copyright expires and starts serving the work to the public from that point forward. This is what to do if a state cares about public domain.
The status quo of corporations abandoning works to bit rot, actual rot, misplacement or fires for decades is strictly worse.
> Require by law all who desire copyright protection to register the work with a governmental agency and place a copy of the work in escrow at an archive as a condition.
You’re just repeating what I already wrote. By all means, call your representatives.
It's the same. "Fail closed" means you can "just" set the system time to be before the expiration date, "fail open" means you can just set the system time to be after.
Either way, having an expiring decryption key is just security theater that harms users.
Spoofing that now gets you in trouble with the FCC as well as the DMCA.
GP’s point stands, you can’t enforce a time lock with cryptography primitives. That’s the fundamental issue with DRM - you’re trying to restrict someone from getting your ciphertext, while at the same time allowing them to get to it if they meet certain (non-cryptographic) conditions, which standard cryptography just can’t do.
That's the point I was trying to make; if someone accidentally pushed a broken update, that sucks, but its not the first or the last time it will happen, and at least there's a clear path to it getting fixed and someone being paid to do it. The cert being expired and the only company who would have been in charge of fixing that not really caring anymore sounds to me worse from pretty much any possible point of view, and selling a product that will stop working if you decide to stop servicing it seems pretty terrible.
This kind of thing is all over the consumer world. In a way it's cathartic to see it hitting businesses too.
If you’re not in Central Texas, you likely have a similar, beautifully-restored old theatre available for similar rental arrangements.
The Beltonian: https://thebeltoniantheatre.com/
How frequently does Sony change its identity. They should have a 999 year cert expiration and then check a revocation list in the off chance they Sony gets its private keys rooted.
That needs to change before any trickle down effect to projector hardware can happen. But there’s no incentive for studios to change the way they given their IP because they benefit from the status quo