Researchers tested AI watermarks and broke all of them

For example, HDCP is a DRM scheme where Intel convinces (or legally requires) every manufacturer of HDMI output devices (e.g. set-top boxes, Blu-ray players) in the world to encrypt certain video streams.

Then, Intel requires manufacturers of HDMI input devices (e.g. TVs) to purchase a license key that can decrypt those video streams. This license agreement also requires the manufacturer to design their device such that the device key cannot be easily discovered and the video content cannot be easily copied.

Then, Intel gets media companies to include some extra metadata in video media like Blu-ray discs. This metadata can contain revoked device keys, so that if a TV manufacturer violates the terms of the license agreement (e.g. leaks their key, or sells a device that makes copies of video content), that manufacturer's TVs won't be able to play new content that starts including their key in the revocation list.

Of course, Intel's HDCP master key was either leaked or reverse-engineered, so anyone can generate their own valid device keys. Intel will probably sue you if you do this, I guess.

(though if you have lots of time/effort/money you could still extract the key)

We are starting to see adoption of software supply-chains with SBOMS, albeit imperfectly. We are starting to see increased adoption of things like DMARC in the email space to better authentic the originator of an email. Both are highly imperfect systems ... but you can start kludging something together ... and if the incentives are there I think you can build out more of a workable system.

I've wanted to build a product in this space ever since I heard about deepfakes. Mix of keybase and appropriate file hash, and hash gen for subsets of sections of video. Maybe it needs to be a protocol, maybe a product, not sure, but the need seems apparent to me.

It's not the cryptography which is the problem. It's, who do you trust with the signing keys? The list inherently has to include every camera maker, despite that industry generally not having a great security culture, as well as every camera's country of origin, and every country with a security service capable of infiltrating some other country's camera maker. Which is probably all of them.

Worse, the keys have to be in the camera. Every camera. Break one of any model and you can forge images with it. Break one of any model and publish the break and you call into question every image from every camera of that type.

Then, even if a camera hasn't given up its keys, someone can use it to take a picture of a picture.

None of this requires a cryptographic break of public key signatures.

Perhaps something like this is what your hostile responder was thinking of.

My guess is likely because it seems like this would be impossible to implement without adding DRM to the smartphone and/or locking down Open Source image editors out of the attestation process. You would need to prevent access to the software, firmware, etc... otherwise the device could be virtualized or the program recompiled to circumvent the signature.

And for obvious reasons there's going to be pushback to adding that kind of DRM to smartphones. The tech does likely exist; this sounds to me like just normal attestation? It would likely hook into something like the Play Integrity API. A lot of people already hate the Play Integrity API though.

It's not the tech that's the problem, it is as you say, that people are hesitant to do it because it would require locking down the phone's software stack in a way that is widely understood by many developers and user advocates to be anti-user and in contrast to user rights to control their own devices and load their own software and/or firmware onto their devices.

I could maybe see an argument introducing some kind of signature to a raw camera input in firmware before it ever reached the user at all -- mostly just because devs seem to have given up the fight about custom firmware on a phone in general. But if you're talking about the phone signing the image after light editing like a crop has happened, at that point you're talking about moving this signature into user-space code, and while I'm sure that problem could have been explained better to you by the devs, it's not surprising to me at all that you'd get a hostile response to that suggestion because I don't see how it would be possible to do that without locking down user-space code.

Unless you have reason to trust Bill himself you can't trust that he actually took the photo, or that it isn't ai generated. Although knowing that Bill isn't tech savvy enough to do those things might be enough.

The Washington Post might not trust its photographers completely either (journalists making stuff up happens[0]), so they too might want proof the photos they're getting are real.

[0]: https://www.nytimes.com/2003/05/11/us/correcting-the-record-...

If I see a photo on twitter claiming to come from the Washington Post, it might not be.

If I see a photo in my facebook feed of a rioter, did it come from poster, or are they just reposting something else? Did that repost come from a newsource I trust, like the WP in this case, or from some reddit post, maybe edited or synthetically generated?

> Maybe they're showing you something made by AI that isn't real, but as the owner of their own signing key, nothing would prevent them from signing an AI-generated image

That's right. This only helps narrow the source down, then you still need to decide if you trust the originator. But I think a lot of the problems we've seen with social media disinformation is the wide dispersion of content claiming trustworthiness from a reputable source, falsely.

My take is that proving authenticity might not be something we can do with any degree of accuracy in a general sense. So if that is infeasible, then we need _some_ kind of mitigation. Something like CAI allows us to make the an assessment about the how much trust to give an informational source, probably taking into account multiple factors (known exploits in the source device, reputation of originator and what claims are be attached in the metadata). This might allow me to accept that a given video originated from a local tv station, rather than tiktoker edit, but I still need to asses if that station used genAI or has been compromised or whatever else. But that seems a much narrower reputational problem, that also will be contextual.

If you create a digital record, then sign it, then that signature is only an attestation of may claim you make, not evidence of that claim. That is the problem with relying on technology to establish trust - the moment you attach an economic benefit to a technology you incentivize people to circumvent it, or to leverage it to commit fraud.