Preserving trust in photojournalism through authentication technology

https://www.reutersagency.com/authenticity-poc/

by rbanffy • 3 years ago

58 61 3 years ago

reutersagency.com

31337Logic• 3 years ago

This is actually more important that must people might think. Thanks for posting.

verisimi• 3 years ago

That horse has bolted.

The reason is that this trust was misplaced in the first instance.

akoboldfrying14• 3 years ago

That horse has bolted.

I don't follow. Sure, existing images can't be retroactively made verifiable, but tech like this can stem the tide from this point on, and that is useful.

The reason is that this trust was misplaced in the first instance.

I don't follow this either. Trust in photos? It has always been appropriate to trust a photo in proportion to the difficulty of faking it. Are you commenting on the fact that it has recently become much easier to fake a variety of photos (deepfakes, etc.) but a large fraction of society isn't yet wise to this?

8note• 3 years ago

The trust is misplaced because while the photo might be accurate of what the photographer saw as they clicked the button, nothing says its representative of the overall scene, or that a different picture of the scene could show a very different description.

For an example, consider a side on closeup of a trump campaign speech vs a top down view zoomed out of the whole park.

Photojournalists can choose which pictures to use to make an argument, and people are too trusting that there aren't alternatives that more strongly support a different argument

The photo doesn't have to be untrue to be misleading

sexy_seedbox• 3 years ago

Uses Filecoin

mceachen• 3 years ago

That's an odd* implementation decision.

Gpg is well established and eminently applicable here. Both the camera hardware as well as the photo journalist could sign the image data payload, and embed the signature in metadata, especially if the camera hardware accepted new keys. Trust chains could be established both via their publisher and the camera manufacturer.

But let's be real: no one will bother to validate anything.

* I'm being diplomatic

woodruffw4• 3 years ago

GPG is “well-established” in the sense that it’s old; it’s not considered a modern or well-designed digital signing (or encryption, or trust distribution, etc.) scheme.

I think there are significant issues with establishing the “authenticity” of digital artifacts in any scheme, but GPG would probably make things worse rather than better here.

b0afc375b5• 3 years ago

What are the modern / well-designed alternatives?

backendanon3• 3 years ago

GPG is not good now? When did that happen?

initplus• 3 years ago

This is a misguided attempt that will fail - all signing the image in camera does is verify that those pixels were sent by the camera sensor.

It’s trivial to work around this and create inauthentic signed images by staging a fake scene, or doctoring an image and then feeding the doctored image into the camera sensor.

For more details see https://www.hackerfactor.com/blog/index.php?/archives/919-Cl...

1MachineElf• 3 years ago

Fake scenes and misplaced cameras are old problems that we already have some solutions for. Since the idea here is to solve the separate and new problem of deepfakes, I don't think this criticism makes a strong case against digital signatures in photography.

turnsout• 3 years ago

Yeah, couldn’t you simply rephotograph a doctored image off a sufficiently high-res monitor?

akoboldfrying14• 3 years ago

You could, but if you got busted doing that, your reputation would take a hit. Everyone would know it was you because you own the camera with that private key. (To wriggle out of it, you would need to claim that either your camera was stolen before the photo was taken, or that Canon/Reuters's private key was compromised. The former claim would be harder if there was, e.g., a second digital signature stored in the JPEG showing that you confirmed your identity with a fingerprint 10 minutes earlier.)

Also: Could you, actually? Maybe photos of monitors have "tells" that can be detected with some kind of image processing.

amadeuspagel• 3 years ago

Seems harder then using photoshop or AI.

backendanon3• 3 years ago

Agreed, it's no better than using a fingerprint to secure a device.

akoboldfrying14• 3 years ago

But any trickery employed is traceable back to that specific camera, meaning that the camera owner's reputation is on the line if it's discovered.

Will that reputational risk actually have any teeth? That's up to us (society at large).

fnordpiglet• 3 years ago

That would require a conspiracy by someone with physical access to the camera. Spoofing the GPS would require even more elaborate techniques. At a minimum if you trust Reuters and their camera people, you know the images taken were taken by them in their custody at those locations. That’s a lot more than we have now.

GauntletWizard• 3 years ago

That's already what we have now. Reuters stakes their credibility on this. They just don't have any.

mmis1000• 3 years ago

Spoofing the GPS

You can already do it now. Somebody even sells premade ones because some people what to screw up Pokemon go players. And it even already caused safety problems. It's the easiest thing of the whole part. Modifying camera require skills. Spoofing gps can be done with a gps spoofer that you may be able to buy somewhere.

instagraham• 3 years ago

It adds a layer of difficulty for fakery. At the very least, such a signed image is a better "source" of truth than an unsigned jpeg from Telegram. We will enter and perhaps are already in an era where you need to build a habit of verifying photographs that proclaim some form of truth.

It’s trivial to work around this and create inauthentic signed images by staging a fake scene

I'm not sure what the implication of this is. Reuters is attempting a basic technological solution to a technological problems (images can be duplicated, altered and reshared by non-Reuters parties for malicious purposes).

Someone staging a fake scene is not a technological problem that can be solved (though I imagine some amount of depth information and geo-data in the image would help)

WiSaGaN• 3 years ago

Unfortunately, you don't need a fabricated scenario to convince people to believe the opposite of what is true. Media outlets routinely select which facts to report, influencing public perception. While technical professionals are often meticulous in verifying the accuracy of information, even they can't employ Bayesian methods to arrive at the truth if the evidence presented to them is already filtered.

dataangel• 3 years ago

you can prevent feeding the doctored image into the sensor if the camera also senses depth, and only signs the image and depth information together. this is how they prevent a photo from unlocking face id on a phone

solardev4• 3 years ago

If the edit chain is private, does this mean that there's no way to validate the edits Reuters itself did?

akoboldfrying14• 3 years ago

I would expect as a baseline that some third party (maybe not necessarily Joe or Jane Public, but at the very least a subpoena-wielding lawyer) could require Canon to produce the original raw camera pixels, and check that they match the signature in the final publicly available JPEG. At that point, this third party would have access to the first and last stages of the image processing pipeline, which is likely enough to decide whether the edits were legit.

meling2• 3 years ago

Didn’t read all the details, but isn’t the point of this thing to store the original in a publicly accessible storage system (storj and filecoin is mentioned). There should not be a need to involve Canon or a third party. This is for verifying published photos after all.

RcouF1uZ4gsC• 3 years ago

A couple of questions that come to mind?

1. How will the signing key in the camera be protected? Are camera manufacturers a SPOF?

2. Based on the following quote:

Editors then work with the pictures, and each successive modification or edit creates a new record in a private database (ProvenDB) that is indexed to the original registration.

How do you ensure that one of the modifications was not "replace all pixels with the one generated by AI", or even "Replace Russian flag with Ukrainian flag"

I only see this possibly working if the new organization releases the raw signed photos to the public. Otherwise, the edit step can do anything.

akoboldfrying14• 3 years ago

Including a digital signature of the raw original in the final image is implicitly a promise that the raw original can be produced on demand (nonrepudiation [0]). Maybe not just anyone can make such a demand, but there would need to be someone (e.g., a court judge) who can.

0: https://en.wikipedia.org/wiki/Digital_Signature#Non-repudiat...

throwaway58480• 3 years ago

The problem with photojournalism is not that people don't trust that the pixels haven't been doctored.

https://www.washingtonian.com/2017/01/20/searching-metaphor-...

akoboldfrying14• 3 years ago

Alternatively it could be there that there is more than one problem with photojournalism, and the article describes a solution to just one of them -- but an important one nevertheless.

kmeisthax• 3 years ago

Editors then work with the pictures, and each successive modification or edit creates a new record in a private database (ProvenDB) that is indexed to the original registration. This allows edit logs to be kept private, but these logs also have their authenticity records registered on the Hedera public ledger.

How exactly do you keep the edit log private without completely losing the chain of authenticity here? One of those edits might be to, say, double the size of a plume of smoke or change a signal flare into a set of missiles[0]. All you have is a promise that at some point, someone opened a real image in some kind of editing software.

The inclusion of a bunch of blockchain nonsense to store the verification also smacks of amateurism. You don't need a public chain with financial costs attached to secure photos you validate yourself. You can just publish a bunch of hashes and a hash of the prior block. Certificate Transparency does this and it works.

[0] https://en.wikipedia.org/wiki/Adnan_Hajj_photographs_controv...

akoboldfrying14• 3 years ago

Provided the signature of the original raw pixels is left in the final JPEG, I think Canon/Reuters can be expected to produce those original bits to any sufficiently curious/legally authorised third party, who can verify the signature to check that they are indeed the original bits. At that point said third party has the initial and final images, which is likely enough to conclude whether the edits were legit (the chain of edits themselves isn't as interesting).

Mostly agree on the blockchain shenanigans, though I suppose using an external blockchain allows you to prove that the image was taken before a certain point in time.

solardev4• 3 years ago

I don't see how this could work, unless they're using some sort of tamper proof perceptual hash (does such an algorithm exist?). If they change any of the pixels in their edits, it's not going to match the original signature. If they compress it to jpeg it'll have a different signature. And nobody's going to request the huge RAW files for every photo.

So this scheme can work to ensure that you're seeing the Reuters published version, not that Reuters itself didn't edit it after the camera took it.

woodruffw4• 3 years ago

The underlying content provenance scheme here (C2PA) was presented at this year’s RWC[1].

[1] https://iacr.org/submit/files/slides/2023/rwc/rwc2023/13/sli...

akoboldfrying14• 3 years ago

This is really cool -- if done right, it has the potential to massively decrease the incidence of false and misleading photos in the world, by massively increasing the reputational risk associated with making and distributing them. I hope regular people start to pay attention to this kind of provenance, since that's where the effect will come from. Time will tell.

(Also, I'm really cool for predicting ~5 years ago that this specific tech would happen -- bringing my count of successful tech predictions to 1.)

tbrownaw• 3 years ago

So how do you do this if you're documenting something that you'd get in trouble for exposing and don't want publicly traceable back to you?

CatWChainsaw• 3 years ago

That's the neat part, you don't. And thus the "problem" of whistleblowers is solved.

bhawks• 3 years ago

Living in a world where we only trust photos from official photojournalists because everything else may have been doctored is not a good outcome.

rbanffy• 3 years ago

We already live in a world we can't trust photos from everyone who calls themselves official photojournalists.

I've seen photos of the recent nazi rally in Orlando that were very slightly manipulated to darken the skin of participants to imply they were, in fact, "infiltrated BLM or Antifa".

Anyone could use this system or a similar one - if the sensor signs the image with its private key anyone can trace a raw image to a specific sensor and, therefore, to a specific camera. If that image (or enough hash bits it becomes impractical to fake the data via collisions and still have a recognizable image) is placed on a public ledger, you can prove those pixels are yours and were taken at or before the moment in time they were added to the ledger. If the camera is part of a larger system, such as a phone, the software can add your own credentials to the raw image data, proving it was you who took the picture (unlocking the phone with, say, your face).

I would not, however, want my personal family photos to be trackable like that. EU restrictions on images already took away a lot of my joy of photographing people.

hulitu• 3 years ago

Preserving trust in photojournalism

To preserve something, you have to have it first.

mattdesl• 3 years ago

Relevant, using ZK SNARKs to authenticate edits without reliance on a central point of trust[1], blockchain in this case would be optional but perhaps appreciated for distributed & decentralized storage and verification of ZK proofs.

[1] https://medium.com/@boneh/using-zk-proofs-to-fight-disinform...

somishere• 3 years ago

I mean, all the attestation here does is say this photo came from this person / camera. Like a hardware-backed NFT. The trust ultimately lies with the photographer and, by extension, the org they're working for at the time. I'm not sure how different this is from Reuters just publishing the photo and archiving the link on wayback. Any future versions can choose to use that link as provenance, an eyeball is all that's needed. Complex technobabble won't stop screams of "fake news."

BearhatBeer• 3 years ago

Canon and Nikon both sell verification kits which can be used to cryptographically prove that a photo wasn't tampered with. Although these kits cost money, it seems it's just a flash drive with special software on it.

Preserving trust in photojournalism through authentication technology

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