[AnthonyMouse]

> The cryptography to support this has been around for ever

It's not the cryptography which is the problem. It's, who do you trust with the signing keys? The list inherently has to include every camera maker, despite that industry generally not having a great security culture, as well as every camera's country of origin, and every country with a security service capable of infiltrating some other country's camera maker. Which is probably all of them.

Worse, the keys have to be in the camera. Every camera. Break one of any model and you can forge images with it. Break one of any model and publish the break and you call into question every image from every camera of that type.

Then, even if a camera hasn't given up its keys, someone can use it to take a picture of a picture.

None of this requires a cryptographic break of public key signatures.