[dooglius]

It's a genuine question, I don't have an argument for impossibility or anything, I just don't see how revocation could practically be done. In scenario A, Joe Schmo buys a camera, happens upon a powerful politician in a compromising situation, and uploads the video to YouTube with a digital signature. In scenario B, Joe Schmo buys a camera, actually works for the NSA, uses an electron microscope to extract the private key, and stamps a digital signature on a forged video, uploading that instead. How would any third party be able to differentiate between those? I could imagine potential avenues for solutions (e.g. maybe you could use quantum entanglement to make some sort of tamper-proof chamber around the key in hardware?) but then we're pretty far afield of straightforward PGP/TLS. Not to mention the problem that an adversary like the NSA could just get inside the ASIC fab and copy keys from the machine that prints them.

[DoctorOetker]

make a distinction between cameras for fun, and cameras for undercover investigative journalism by journalists or citizen journalists.

the first type of camera is the one we have today, the second type would be more expensive, need to stay connected to the group consensus protocol, and need to stay powered, so journalists will be lugging extra batteries, and the camera would have 2 battery ports for switchover...