Another option related to the checksum solution is that camera manufactorers could implement a system on the physical camera where the raw file is tagged with some checksum/stamp and the same is stored on the device. In a situation where the validity of the photo/video in question, you could use the raw files and the physical device that captured it as the proof.

I’m sure we will see multiple attempts to solve this, whether it be adverserial “de-fake” AIs, some physical verification or something completely different. It will be interesting to see what work and not, and what may turn out to become the standard way of verification