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Comment by smt88 | Hacker News Reader

I worry about the same thing.

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.

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You can have an immutable centralized/federated system without using "crypto" though "proof-of-work", there are databases out there that provide immutable storage that don't require this overhead.

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 need cryptography for hashing and verifying the integrity of any copy of the database.

You probably don't need proof of work, you're right.

Proof of work is not needed, just a pool of time servers that you can make a quorum out of. We're working on exactly this on top of roughtime (https://roughtime.googlesource.com/roughtime) for a future version of QR Date (https://qrdate.org/)

Great discussions! Some thoughts:

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

I've been thinking about this -- original video could be the NFT, and the purpose of the system would be to verify / validate the content (instead of the weird pyramid schemes it's being used for today).

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.

In that scenario, where is the line between a deepfake and satire?

That's an irrelevant issue. The issue I'm talking about is only whether a viewer can determine if a video has been edited.

Once they know it's edited, they can decide for themselves whether it's enjoyable satire or an attempt to deceive them.

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