DavriellelounaWatermarks offer no defense against deepfakes, study suggests
I think maybe an update to the image format standards, where it like somehow includes a hash of the instrument that has taken the photo and video, and thus, only such media that can be verified to have been taken by a physical instrument can be used in like legal matters, or reporting or journals.
There are already plans for metadata signing. I think some high end Canon cameras might do it already. It basically allows proof (via public private key of the hash) that a particular camera took that photo.
The idea is that you can create a chain of custody with an image. Each edit requires a new signature, with each party responsible for verifying the previous chain, to protect their own reputation.
It’s far from perfect, but will help a lot with things like legal cases.