A rooted phone could not, but anyone with a bottle of acid and a microscope could. Or as I’ve said, a nice optics setup and a high quality projector.

My point being that trusting the camera chip does not help much. But, of course, it would block the easiest software attacks like we have seen so far.

That would be my guess as well.

I’m not a researcher in this field, so I don’t have anything substantial to suggest. My opinion is that it is unsolvable.

No matter what you try, sufficiently powerful entities will be able to modify the sensor to sign images of anything they want to pass as real (or just use a very high quality projector)

It might be better that we are all always weary of an image being AI at this point.

This is a terrible idea. So of course it already exists https://c2pa.org/

It’s already being exploited https://www.da.vidbuchanan.co.uk/blog/android-c2pa.html

We need a solution but that’s not it.

I think google hides an additional mark in their own edits so the tool can perform an actual check in this case.

They would not detect any AI edit from other providers.

There are tools to remove these hidden “signatures” E.g. https://github.com/wiltodelta/remove-ai-watermarks

I’m not commenting on the ethics.