Deepfakes are readily understandable as a problem for politicians. Politicians are experts in public messaging; this technology has the ability to alter previously-immutable messages.
Then when viewing the video in the future, you can check it's hash and compare it to the one stored on chain to be sure the video wasn't tampered with.
Every type of video authentication system I've ever heard proposed can be defeated by simply pointing a 'trusted' video camera at a screen playing a fake video.
Video could be 'authenticated' by post facto tracking of particles to validate both continuity and plausible velocity deltas based on generated model of air currents. It wouldn't eliminate the possibility of deepfakes, but would drastically increase cost of production.
Similarly, I predict that cameras will increase in resolution past the point of utility for human vision: tetrapixel camera video would be extremely expensive to produce without leaving tiny artifacts.
This obviously wouldn't solve the 'no fake videos' problem but would least mean 'this video isn't fake' for a select subset. There could be tiers of information in the future where this audited media is weighted higher.
That's a good point. But I'm imagining situations where the camera itself is a reasonably secure device. For example, a city CCTV camera or a police body worn camera.
If a video stream can be securely (cryptographically) matched to a particular device, with an unforgeable (blockchain?) timestamp, it would increase confidence in video evidence presented in court, for example.
The credibility of still footage has dropped before. I don't know where that leaves us for authentic media...