New research from the University of Waterloo's Cybersecurity and Privacy Institute demonstrates that any artificial intelligence (AI) image watermark can be removed, without the attacker needing to know the design of the watermark, or even whether an image is watermarked to begin with.
In order for it to be traceable with a public key, it needs to be signed with the private key. That means the private key has to be on the camera. That means it can be extracted from the camera and leaked.
Maybe. There are ways to assign a private key that is not easy to extract. a chip that creates a private key on first poweron and then saves to internal memory for example.
Not easy to extract sure, but is it secure enough for you to claim that it hasnt been leaked and so forms a secure chain of custody? Once one has been leaked then that can be used to sign any fake pictures you like. I woudnt buy that for anything for serious than is this meme picture real.