How does the signature help? It only proves that the video hasn't been altered since [timestamp]. It doesn't prove that it wasn't AI-generated or manipulated.
Signatures are also able to (mostly) signal that a specific device (and/or application on that device) captured the video. It would be possible to check if a video was encoded by a specific instance of an iOS Camera app or AfterEffects on PC.
Everything else - corroboration, interviews, fact checking will remain as they are today and can't be replaced by technology. So I imagine a journalist would reach out to person who recorded thr video, ask them to show their device's fingerprint and ask about their experience when (event) occured, and then corroborate all that information from other sources.
When the news org publishes the video, they may sign it with their own key and/or vouch for the original one so viewers of clips on social media will know that Fox News (TM) is putting their name and reputation behind the video, and it hasn't been altered from the version Fox News chose to share, even though the "ModernMilitiaMan97" account that reshared it seems dubious.
Currently, there's no way to detect alterations or fabrications of both the "citizen-journalist" footage and post-broadcast footage.
If I have a CCTV camera that is in a known location and a TPM that signs its footage, I could probably convince a jury that it’s legit in the face of a deepfake defense.
That’s the bar- it’s not going to be infallible but if you don’t find evidence of tampering with the hardware then it’s probably going to be fine.
This might be worse than nothing. It's exactly the same tech as DRM, which is good enough to stop the average person, but where tons of people have private exploits stashed away to crack it. So the judge and general public trust the system to be basically foolproof, while criminals can forge fake signatures using keys they extracted from the hardware.
