In the long run, I wonder if all video will be signed via blockchain-or-other-trusted-3rd-party. You'd need everything from the camera to the the editing software to support it though.
Unless somebody builds a kind of 'pseudo-random-generator' chain where the internal state is huge, changes substantially each tick and is very expensive to compute, so that it becomes infeasible to store or recompute (a large number of) previous states for anyone but the most powerful players.
You could then use that internal state as a private key to sign what you want and only keep the corresponding public key and a signed date+time to proof the veracity. The public keys themselves would need to form a blockchain in the traditional sense, so you can verify their integrity without the previous internal states.
If you wanted to go all-in with the verification, you'd probably also want to show something containing the date+time in the video, together with some complicated physical effects that are hard to fake.
Well, just thinking out loud here, but it seems like it might work :D
I vaguely recall reading somewhere several years ago about some cameras which signed the photos they produced, so one could prove they came directly from the camera and weren't edited. IIRC, it was in an article about these signatures being broken, though I don't recall the details (perhaps it was by dumping the signing key from the camera firmware?).
Early digital cameras could be fingerprinted by looking at dead pixels (there are over a hundred million ways to have three dead pixels in a one megapixel camera, so if these are uniformly distributed, that, in the early days, when few cameras existed, have almost guaranteed uniqueness). It wouldn’t surprise me if that still is possible by looking at minor variations in light sensitivity across pixels (that might require having access to lots of photos by a single camera, though)
Why would the blockchain help here? Basically you need public private key pairs where the private key exists only in silicon and the public key is associated with a serial number. Normally the serial number is trivially associated with the customer who ultimately purchases the hardware especially if the camera is part of a phone with an active plan.
It seems like this trivially works better with a centralized database especially since you don't necessarily want to make all of this data public. The general public needs to know that this is a true and accurate photo that hasn't been edited taken on such and such a date. The authorities with a warrant might well need to know that it was taken by a device owned by bob.
CPLX|5 years ago
Otherwise you can just feed whatever video you have in mind into the first stage of that chain you’ve created and say you were there when it happened.
mckirk|5 years ago
You could then use that internal state as a private key to sign what you want and only keep the corresponding public key and a signed date+time to proof the veracity. The public keys themselves would need to form a blockchain in the traditional sense, so you can verify their integrity without the previous internal states.
If you wanted to go all-in with the verification, you'd probably also want to show something containing the date+time in the video, together with some complicated physical effects that are hard to fake.
Well, just thinking out loud here, but it seems like it might work :D
cesarb|5 years ago
Someone|5 years ago
michaelmrose|5 years ago
It seems like this trivially works better with a centralized database especially since you don't necessarily want to make all of this data public. The general public needs to know that this is a true and accurate photo that hasn't been edited taken on such and such a date. The authorities with a warrant might well need to know that it was taken by a device owned by bob.
eivarv|5 years ago
We can't inherently trust content on the basis of its medium.