I think "blockchain" (or even just a signed, immutable, public database) is mostly a solution in search of a problem, but I do think it may have an application here.
If you can hash a video when it's recorded and publish the hash with a timestamp that can't be forged, you can at least prove that this video existed at least as long ago as that stamp.
That allows you to invalidate any deepfakes produced on top of that video that have later timestamps.
It's not perfect, but it might be one weapon against this stuff.
Providing api access to a signed immutable database makes sense... but I'm not sure how much sense utilizing existing popular cryptocurrencies would make (e.g. bitcoin, etherium)
You probably don't need proof of work, you're right.
First, there are multiple solutions to this problem, all need to be explored and many will have a part in the future. Bad actors will do everything they can to find a way around every solution.
Second, for the hashing approach, have a look at "Perceptual Hashing", it's a way to hash content like a an image, even if the resolution changes.
Where to store the hashes? A centralized server is probably fine, but there is always a risk of a bad actor exposing it somehow. A secure blockchain can work better. But if you go that route, might as well go with the most secure blockchain. POW is generally more secure than POS. And currently the most secure blockchain is Bitcoin. So one solution is to batch hashes together and write them with a Bitcoin transaction in some cadence.
-Ali
The issue is with the hash, esp with lossy compression algos. If the video is re-transmitted somewhere, its content remains effectively "the same" (eg, it is that particular person, saying these exact things, at some specific time and place). A regular hash will not match as the video is different bit-to-bit though.
So for this scheme to work, we would need some kind of a "domain hash", something that is very precise in aspects that matter, and fuzzy in ones that don't. In case of videos, one dimension could be the text transcript. But even then it falls apart pretty quickly.
Once they know it's edited, they can decide for themselves whether it's enjoyable satire or an attempt to deceive them.
We are working with few partners (including Microsoft) who are interested in integrating our solution. We are focused right on supporting large organizations (companies and governments) that need to scan user generated content at scale.
I have submitted my resume: https://cphoover.github.io/
Have you also considered either offering a browser plugin to display contextual warnings attached to video elements? Or thought of working with browser makers? The web/social media is where a ton of fake media is propagated. It would be good if large platforms (fb/twitter/yt) integrated with such service, but also individuals should be able to protect themselves.