Sensor supplier could embed the crypto in the hardware as close to the imager as possible and issue signing keys for each device. OEM would write firmware to extract that from the camera bitstream and dump it into the metadata of the image (something along those lines anyway)

The image and signature could be added as authentication layers and then a third layer added to allow post-production (crop/levels/etc). Right click in your browser to 'see original image' with a little padlock in the corner. Ideally this would include GPS info to reduce likelihood that someone would just project a desired image on a screen and photograph that.

That assumes a lot of trust in OEM providers, and there would be a lot of incentive to compromise the key.

Agreed. Nothing is foolproof. It would make it harder for Joe Sixpack to spoof images, I guess the question is whether or not that's better.

Yeah, joe six pack is not the one I am worried about. Nation states are.

Sounds like DRM. Also, it wouldn't be too hard for the people who actually want to hack it.

Well, no, it won't.

It will however make sure that you're watching actual Obama 2, and not some computer simulation of him doing some disgusting thing.

Yes, this is terrible. We're going back to the "dark ages" when a horrendous crime could happen in broad daylight around multiple witnesses and nobody would be found or sentenced.