More seriously, I think that digital photos, and especially low-res surveillance camera coverage, will soon be inadmissible in any reasonable court, because tools like this would allow to forge such evidence in very natural-looking ways.
Fakes will be relevant for Twitter, TikTok and Co., where random videos are posted and distributed without sources, heavily edited and compressed, such that it is impossible to tell if that video ever started out as a real video or a fake. But in court the whole thing starts to fall apart the moment they ask where that video came from.
We will still need a centralized party that holds the secret keys for validation through
Some of them possibly could be updated, but this will take time. Securing the keys within them is also going to be a problem; not all of them have a TPM.
Also, what about someone putting a screen just in front of the sensor?
A private key is generated on device and never leaves it. It sits inside a TPM or equivalent.
The public key is pushed to a well-known site, visible to all.
Every shot is signed by hashing the bits into a reasonably short string (say, using sha512) and then encrypted with the private key.
Anyone can now decrypt the hash, and compare it with the hash they computed from the bits.
The problem, of course, is that any transformation whatsoever breaks the signature. You can't adjust levels and contrast, you can't even crop. Maybe it's a good property.
You definitely don't want one single leakable entity.
And, of course, the easiest to falsify evidence (eyewitness testimony) is still admissible.
That's why you have to provide support for provenance, all of which is subject to examination and counterevidence.
https://daily.jstor.org/forensic-dna-evidence-can-lead-wrong...