>If you can sign a video then you can sign a doctored video.
I don't understand your point, you wouldn't sign a doctored video unless you wanted to do so. It's entirely possible to apply the principles of PGP to video.
>If it's only your camera that can sign the video, not you directly, don't be fooled that it will be possible to protect the private keys in the camera from extraction.
I doubt this would be the solution on which the world settles.
When you publish a video of you speaking at a public event, you sign it. When someone else publishes a doctored video of you, you do not sign it.
This alone doesn't protect you in the case that someone speaks and then later intentionally doctors and signs the video in order to change what they said. In this case trusted third parties (e.g. news organizations) could sign videos as well. A set of signatures taken together can provide trust.
I don't understand your point, you wouldn't sign a doctored video unless you wanted to do so. It's entirely possible to apply the principles of PGP to video.
>If it's only your camera that can sign the video, not you directly, don't be fooled that it will be possible to protect the private keys in the camera from extraction.
I doubt this would be the solution on which the world settles.