> For example, a screen attack still works: photograph a screen displaying an AI image and you get a signed photo of a fake. But it's always nice seeing big actors interested in addressing this problem.

Yeah, very nice. So this whole idea basically doesn't work - but we get a new stealth way to embed metadata in an image that can be used for tracking...

(And a new narrative why cameras need to have TPMs and locked-down firmware as well)

Photos of photos has always been a problem.

In days of old, a Polaroid photo was considered "proof of capture".

I've got a Polaroid daylab 35 plus sitting in storage somewhere (https://www.instantoptions.com/wp/faqs/daylab/). You can project a slide through it onto Polaroid film, expose it, and have the image there.

I was also able to find a company that did slide printing. It was possible to send them a digital image and they'd send you back a slide with that image... which I then used to make a Polaroid of that image.

I had a classic 600 Polaroid photo of a UFO landing.

Couldn't the camera encode information from the depth sensor and prevent this.

That signature contains time and optionally gps coords, and taking photo of a screen is not simple. So overall does solve some problem

ps:most important: cam/lens settings also in the digital sig, what for a screen is different