Yes but the idea is that you trust the camera which unique and works as a physical private key.

> Yes but the idea is that you trust the camera which unique and works as a physical private key.

You're pushing a (bad) technical solution to a social problem.

Cameras that cryptographically sign their output will not solve anything. The idea has more flaws than it's possible to list, but here's a big one: do you really think a technological gimmick like that would stand up to a nation state? Do you really think the CIA, NSA, FSB, Chinese Ministry of State Security, etc. will not be able to sign whatever the hell image they want with a camera's signature?

Currently difficult to display something a modern smartphone camera will not be able to distinguish from real, right? (Pixel artifacts, lighting too consistent, etc. right?).

It might be doable with an 8k TV and a source video with a lens-distortion applied to generate the opposite expected lens distortion of the crypto camera, so once it's recorded the perspective does not look like it is a recording of a flat video. Depth sensors would help with defeating that idea.

Or you could just smear some Vaseline on the lens and tell people the lens got dirty. It hurts the credibility for anyone who knows about these cameras but I doubt the public would think about it that much.

For sure but if they do it right it will make it hard enough and time consuming enough that only top actors can afford to do it.

Is that good, though? If a hole in a system is exploited by only "the top", it may be disregarded and "the top" will be able to inject anything there, but if it is exploitable by anyone from a wide group, then info from the system will be widely distrusted and communication may work around it?

Also, how to protect a chip from reverse engineering even from all except "top actors"? I remember the price for reverse engineering of certain ICs was between 5 and 7 figures of USD. Don't know about modern IC processes, but it may be affordable for many even for those?