I'm confused how courts will deal with this in the future. We are just entering the age of deep fake voices, convincing ones at least. And there are bound to be plenty of deep fakes that sound like the real person but aren't. Are we now going to be held liable for deepfakes we didn't make? I'm surprised people aren't using this more for divorces and what not. Create a deepfake of your wife and then say "Here's proof…
How do we prove authentic? Same way we prove that a website we visit is authentic. Every recording made will be signed/hashed and be able to validate of the public key of the recording device (every phone will have a key). White House, News Orgs, etc. all will use cameras with public keys so everyone can validate. As soon as only one pixel or frequency changes, it will be invalid/fake.
In the end, all will be even more trustworthy than today (there will be some kind of signed/verification label on every video/audio/media that is original/valid).