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by upofadown 993 days ago
Entities like CFOs and political leaders will have to start cryptographically signing their statements. There is no practical way to detect fakes after the fact.
7 comments

All official materials should primarily be posted on the original authors' websites and signed using asymmetric cryptography. Furthermore, new open standards should be established to enable the presentation of such signatures/verification on well-known platforms like YouTube, FB, etc. These platforms should always provide a clear reference to the original material along with its digital signature.

For example, when watching a video on YouTube containing a speech by the president (provided on an official channel like the White House's), there should be a clear indication that the video has a digital signature and the option to verify it on an independent government website.

There are already coming cameras which sign the data on the fly with help of hardware security modules. Only that can be truly verifiable.

Adding signature after recording works to certain degree, but it still does not guarantee that the content is what the camera saw.

…what the camera saw.

Cameras can record screens.

Perhaps adding a signed channel for depth and/or non-visible light would be the next step.

Currently difficult to display something a modern smartphone camera will not be able to distinguish from real, right? (Pixel artifacts, lighting too consistent, etc. right?).
It might be doable with an 8k TV and a source video with a lens-distortion applied to generate the opposite expected lens distortion of the crypto camera, so once it's recorded the perspective does not look like it is a recording of a flat video. Depth sensors would help with defeating that idea.

Or you could just smear some Vaseline on the lens and tell people the lens got dirty. It hurts the credibility for anyone who knows about these cameras but I doubt the public would think about it that much.

Yes but the idea is that you trust the camera which unique and works as a physical private key.
> Yes but the idea is that you trust the camera which unique and works as a physical private key.

You're pushing a (bad) technical solution to a social problem.

Cameras that cryptographically sign their output will not solve anything. The idea has more flaws than it's possible to list, but here's a big one: do you really think a technological gimmick like that would stand up to a nation state? Do you really think the CIA, NSA, FSB, Chinese Ministry of State Security, etc. will not be able to sign whatever the hell image they want with a camera's signature?

For sure but if they do it right it will make it hard enough and time consuming enough that only top actors can afford to do it.
Is that good, though? If a hole in a system is exploited by only "the top", it may be disregarded and "the top" will be able to inject anything there, but if it is exploitable by anyone from a wide group, then info from the system will be widely distrusted and communication may work around it?

Also, how to protect a chip from reverse engineering even from all except "top actors"? I remember the price for reverse engineering of certain ICs was between 5 and 7 figures of USD. Don't know about modern IC processes, but it may be affordable for many even for those?

There's already things like eyeWitness (an app): https://www.eyewitness.global/

But even hardware can be hacked/bypassed if the effort is worth it.

How would that work with video editing? Like if someone records something and then trims it for length or needs to combine multiple streams. Seems like hardware level verification only goes so far.
For editing it does not matter if you just remove or move frames. Video is just a series frames and each of them are signed, each frame can be validated if the content is unmodified. If the same root key is used for another stream, then frames can be combined easily.

I don't know audio well enough how it happens there. But potentially it can be signed in chunks as well.

Of course, one needs to consider risks if editing can make content appear different than originally intended, when the video as "whole" is not signed. But for that, different entity can be used again.

You do get into issues because video files aren't just raw frames and haven't been for ages. Plus any changes on top of the video wouldn't just pass the frames through beyond the fact that current video encoding would reencode the embedded video when the larger video it was embedded in was exported. You'd have to add support for seamless passthrough of the original frames so the signatures could be validated plus some additional layers if you wanted to enable having graphics on top of the footage.

It would require completely changing how software currently handles video editing in short.

Let's say that camera records in 60fps. Maybe all the data on all the channels can be recorded in chunks of 1/60s and signed separated. Then camera combines it as whole playable video, but then there is a separate metadata for each time/byte offset which have been signed.

At the beginning, camera manufacturers might need to provide their own editors, to make editing possible. How much we can trust the camera holders, if the editor software even allows using the key from the camera for better editing in certain limits?

> video files aren't just raw frames and haven't been for ages.

Does that really matter? You could sign keyframes, and then also sign the differences frame by frame til you get to the next keyframe.

Really?? I imagined this product but thought there must be some reason it’s a bad idea
It could be used to hunt down reporters and whistleblowers if the cameras have to be purchased with an ID. So the very people who would benefit might be forced to strip this extra data to protect themselves.

I wonder if you could use the camera to record deepfaked video and in effect bless a lie. Even just filming a TV set might be enough for low grade blackmail and much more complicated methods are available.

At least as a start after the fact signing will say this video was released by X.
Can’t wait for the first political misstep being blamed on leaked keys.
Isn’t this a problem? Someone can take an actual clip of a speech but because it’s not signed by the speaker no matter how bad the speech, it could be declared inauthentic or deepfake because it has no signature?

For example the whitehouse is known to revise the text of the president’s speeches when he says the wrong thing. If we only have officially released videos where the gaffes and fables are left out, how is anyone to know what he actually said?

We don't have to live in the world where people are maximally naive (even if it seems so today). That also assumes there's not a signed video available of the event, usually things are recorded by more than one person especially a speech by the president.

The biggest risk IMO is that key becomes immediately one of the most important secrets to keep since it holds the promise of validating anything you want to lie about.

Signing keys can be derived from a root key that allows for rotation and revocation. Multiple keys can sign the same content.
Now you have to securely deliver those keys to the cameras and people have to keep them up to date. With smartphones it's a bit easier because that can just be pushed to the phone automatically but for news orgs and other professional outfits their camera's aren't internet connected. So then you have a weird mishmash of deciding if an out of date key is being used because it's been cracked/stolen or if the NBC stringer just didn't update their camera before heading to the event.
Really? How about not using unofficial channels for statements?

I mean, what is new to this problem. Other than it is somewhat cheaper to pair the fake statement with the person responsible reading it out laud.

Department press release -> Reuters -> News paper -> reader

No signing required. The reader can verify the press release of he wants to.

It is different in my opinion.

* Text: You have little (definitive) clue who wrote what. You essentially have to ask the (apparent) writer.

* Photo: You used to have high confidence that a picture shows who appears to be shown. Not 100%, sure, but it's high.

* Video & Audio: You used to have very high confidence that the video including its audio are genuine. It was very difficult to replace video and/or audio.

Nowadays, none is trustworthy by default anymore. You can say: Well, just trust the company or Reuters. Sure, but I don't think anyone cares about this case. It's not controversial. But how will they be able to verify controversial sources?

If they get sent a video claiming to be about Ukrainins killing civilians, and outfits & speech matching that, how can Reuters be sure about anything now? Trust can't be given to the source, nor to the video, nor to the audio, nor to the metadata.

> Photo: You used to have high confidence that a picture shows who appears to be shown. Not 100%, sure, but it's high.

I don’t agree. Many important photos don’t show what we think they do.

The Soviet flag on The Reichstag. When it was taken and what it showed are different to the impression you get looking at the photo. It was taken after the event and the signs of looting were removed. https://en.m.wikipedia.org/wiki/Raising_a_Flag_over_the_Reic...

The flag raising on Iwo Jima was the second flag raised that day. It’s not quite the same once you know that. https://en.m.wikipedia.org/wiki/Raising_the_Flag_on_Iwo_Jima

The famous ‘Falling Soldier’ photo from the Spanish Civil War is now thought to have been faked. https://en.m.wikipedia.org/wiki/The_Falling_Soldier

There are bound to be loads more, and the faking goes way back. The US Civil War has examples where bodies were dragged around and made more dramatic. Added cannon balls in Crimean War photos etc.

This has long been a solved problem out in the real world.

Think back to the Nixon watergate scandal. When the reporters were going to press about that, they made damn sure it was 100% real first. By interviewing varying sources, human trust, etc.

All that really changes is they can't take video and audio evidence as fact anymore. So they have to, in essence, audit the video/audio trail, so they will want to talk to the person that filmed it, make sure the story holds up, etc.

Some technology changes can help with authenticity here, but it's not really a technical problem, it's a human trust problem.

There will be learning curves and maybe one or two of the currently well known and trusted news sources totally burn their brand because they didn't do their homework. Nothing really new though.

But that is out of scope of what you are replying to.

If a CFO makes a statement and that is on the company's website we can have reasonable confidence that the CFO made that statement and we can act on it.

Reporting on a video of unknown (possibly unknowable) provenance is a different kettle of fish.

Ah I see, I forgot the topic of this specific comment thread. Political Leaders could also have similar problems though.

Example - Dictator A says terrible things on video/audio. Of course it's not going to be shown on their nations' broadcast website or in media.

How can the rest of the world make sure the video that was recorded is trustworthy?

The same way we did in the days of print media being the only media?

A network of trusted sources, reporters and newspapers that the public trusts. Eye witness accounts, a preponderance of evidence.

Basically it boils down to the reputation of the individuals involved in the chain of trust.

Personally I'm excited by the prospect that we might get mainstream investigative journalism back in some form.

> You used to have very high confidence that the video including its audio are genuine.

The physical artifacts yes, but not the narrative they were portraying. The “news” media has been spinning fictional narratives with physically authentic video and audio for a long time.

>>>> Nowadays, none is trustworthy by default anymore.

Perhaps that is a good thing. Maybe this is a good excuse to stop and consider multiple news outlets, even if it conflicts with our own opinions, for our news sources.

https://en.wikipedia.org/wiki/Firehose_of_falsehood

The thing about FoF is it gets people to stop believing anything which is very effective for bad actors and far less useful for good actors.

This assumes people are consuming news through official channels which I don't think is true in a lot of cases. For many people, news is whatever pops up in their facebook/instagram/twitter feed, and it's relatively easy to slip fake content in there.
You rarely need a perfect fake because you rarely need to convince everyone, you can often achieve the same goal by just convincing a large group of people.

Also, official channels get hacked too.

It’s trying to solve the social issue of ‘omg react!’ videos and random reshare clips through technical means (proving the clip isn’t original).

Which it won’t. Eventually might be relevant when in a context where someone actually stops and spends time looking at evidence (civil and criminal court cases perhaps?) but those already use chain of custody for evidence because evidence has already been easy to fake for… well forever.

Still should be done IMO though, as it’s cheap and easy and will hopefully make it a little harder (or easier to detect) to do mass faking in the ‘middle’ - like fake IDs for online services, fake blackmail photos, etc.

What happens when the news paper just makes stuff up because they need a more click baity article? People click links on emails without verifying the sender what makes you think readers will track back through the chain you describe to verify anything?

Don't roll your own authentication.

What happens is that the readers lose trust in the newspaper and reads another one.

I guess that is not a new problem either with lying newspapers.

Whistleblowers also can't use official channels.
I think that's a really bad take. The difficulty of making many categories of lies is radically decreasing. That it has long been possible for a well-funded vfx team to do something doesn't mean nothing will change when it becomes possible for anyone with a cellphone and five minutes of free time to do the same thing.
> anyone with a cellphone and five minutes of free time

One could argue that this will be a good thing because deep fakes will be so prevalent (e.g. kids making videos of their parents saying and doing funny things) that the default assumption is that everything is fake until proven not fake.

The default assumption will be, as it mostly is already, that anything you want to believe is true, and anything you don't, is fake.

Thanks to a businessman/politician who turned "news about me I don't like" into "fake news", we got a jump start on that.

Lower trust societies are better if you enjoy living in a warzone and being oppressed by a tyrannical government.
> default assumption is that everything is fake until proven not fake.

This is what it's like living under an authoritarian government. "Of course the government is lying", "Of course the politician is lying", "Of course my neighbor is lying", "Of course the company is providing me with a fraudulent product"

This eventually turns into a kind of learned helplessness and is how you create a crapsack nation/world. "Everything is bad, so there is no reason I should do anything good"

I can promise you that you won't enjoy this world we're creating if you don't live in an authoritarian shithole already.

Why would that be a good thing?
The vast majority of uses for deep fakes is not for content that would appear on an official site: surreptitious videos of CEO/Politician doing illegal or embarrassing behaviour, racist tweets and emails from when they were college students etc.
At the same time, now when a sex tape comes out for someone they can claim it's a deepfake.
But will that make a difference?
Time will tell. I think the answer is yet. I am inclined to avoid naming specific, relatively recent instances, but I think it would be fair to say that we're in a world with very high skepticism of the media and politicians have been taking that into account by claiming that the news is simply lying, that what they're reading is fake, etc.
It cuts both ways. We don't trust the media, and we don't trust the politicians. So when a politician says that the media is lying, we tend to believe whatever we want to believe.

The loss of truth is a serious thing for a society. (Yes, back in the Walter Cronkite days we had less truth than we thought we did. We had more agreed-upon truth that matched reality than we do today, though, and I think the difference matters.)

A great not-quite-unexpected renaissance of PGP...?
I honestly find it suprising that photo's and video's taken with a smart phone are not signed in some way to ensure they are not modified.. Would love to see it become more mainstream, since editing is so easy.
… or do everything in person. You know, like before computers existed.
That just delegates trust to media channels, which are equally as untrustworthy.
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