Would someone have a high level overview or ELI5 of what this would look like, especially for the average user. Would we need special apps to verify it? How would it work for stuff posted to social media
linking an article is also ok :)
CyberSeeker@discuss.tchncs.de 10 months ago
Digital signature as a means of non repudiation is exactly the way this should be done. Any official docs or releases should be signed and easily verifiable by any public official.
otter@lemmy.ca 10 months ago
AbouBenAdhem@lemmy.world 10 months ago
Depending on the implementation, there are two cryptographic functions that might be used (perhaps in conjunction):
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Cryptographic hashes: An arbitrary amount of data (like a video file) is used to create a “hash”—a shorter, (effectively) unique text string. Anyone can run the file through the same function to see if it produces the same hash; if even a single bit of the file is changed, the hash will be completely different.
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Public key cryptography: A pair of keys are created, one of which can only encrypt data (but can’t decrypt its own output), and the other can only decrypt data that was encrypted by the matching key. Users (like the White House) can post their public key on their website; then if a subsequent message purporting to come from that user can be decrypted using that key, it proves it came from them.
Serinus@lemmy.world 10 months ago
a shorter, (effectively) unique text string
A note on this. There are other videos that will hash to the same value as a legitimate video. Finding one that is coherent is extraordinarily difficult. Maybe a state actor could do it?
But for practical purposes, it’ll do the job. Hell, if a doctored video with the same hash comes out, the White House could just say no, we punished this one, and that alone would be remarkable.
AbouBenAdhem@lemmy.world 10 months ago
Finding one that is coherent is extraordinarily difficult.
You’d need to find one that was not just coherent, but that looked convincing and differed in a way that was useful to you—and that likely wouldn’t exist, even theoretically.
CyberSeeker@discuss.tchncs.de 10 months ago
There are other videos that will hash to the same value
This concept is known as ‘collision’ in cryptography. While technically true for weaker key sizes, there are entire fields of mathematics dedicated to probably ensuring collisions are cosmically unlikely. MD5 and SHA-1 have a small enough key space for collisions to be intentionally generated in a reasonable timeframe, which is why they have been deprecated for several years.
To my knowledge, SHA-2 with sufficiently large key size (2048) is still okay within the scope of modern computing, but beyond that, you’ll want to use Dilithium or Kyber CRYSTALS for quantum resistance.
Natanael@slrpnk.net 10 months ago
Public key cryptography would involve signatures, not encryption, here.
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AtHeartEngineer@lemmy.world 10 months ago
The best way this could be handled is a green check mark near the video that you could click on it and it would give you all the meta data of the video (location, time, source, etc) with a digital signature (what would look like a random string of text) that you could click on and your browser would show you the chain of trust, where the signature came from, that it’s valid, probably the manufacturer of the equipment it was recorded on, etc.
ulterno@lemmy.kde.social 10 months ago
Just make sure the check mark is outside the video.
Natanael@slrpnk.net 10 months ago
Browser controlled modal.
wizardbeard@lemmy.dbzer0.com 10 months ago
The issue is making that green check mark hard to fake for bad actors. Https works because it is verified by the browser itself, outside the display area of the page. Unless all sites begin relying on a media player packed into the browser itself, if the verification even appears to be part of the webpage, it could be faked.
brbposting@sh.itjust.works 10 months ago
Hope verification gets built in to operating systems as compromised applications present a risk too.
But I’m sure a crook would build a MAGA Verifier since you can’t trust liberal Apple/Microsoft technology.
dejected_warp_core@lemmy.world 10 months ago
The only thing that comes to mind is something that forces interactivity outside the browser display area; out of the reach of Javascript and CSS. Something that would work for both mobile and desktop would be a toolbar icon that is a target for drag-and-drop. Drag the movie or image to the “verify this” target, and you get a dialogue or notification outside the display area. As a bonus, it can double for verifying TLS on hyperlinks while we’re at it.
Natanael@slrpnk.net 10 months ago
Do not show a checkmark by default! This is why cryptographers kept telling browsers to de-emphasize the lock icon on TLS (HTTPS) websites. You want to display the claimed author and if you’re able to verify keypair authenticity too or not.
AtHeartEngineer@lemmy.world 10 months ago
Fair point, I agree with this. There should probably be another icon in the browser that shows if all, some, or none of the media on a page has signatures that can be validated. Though that gets messy as well, because what is “media”? Things can be displayed in a web canvas or SVG that appears to be a regular image, when in reality it’s rendered on the fly.
Security and cryptography UX is hard. Good point, thanks for bringing that up! Btw, this is kind of my field.
pupbiru@aussie.zone 10 months ago
it would potentially be associated with a law that states that you must not misrepresent a “verified” UI element like a check mark etc, and whilst they could technically add a verified mark wherever they like, the law would prevent that - at least for US companies
LodeMike@lemmy.today 10 months ago
There’s already some kind of legal structure for what you’re talking about: trademark. It’s called “I’m Joe Biden and I approve this message.”
If you’re talking about HDCP you can break that with an HDMI splitter so IDKz
captain_aggravated@sh.itjust.works 10 months ago
Relying on trademark law to combat deepfake disinformation campaigns has the same energy as “Murder is already illegal, we don’t need gun control.”
pupbiru@aussie.zone 10 months ago
i’m not talking about HDCP no. i’m talking about the certification process for HDMI, USB, etc
(random site that i know nothing about): pacroban.com/…/hdmi-certifications-what-they-mean…
basically you’re only allowed to put the HDMI logo on products that are certified as HDMI compatible, which has specifications on the manufacturing quality of cables etc
in this case, you’d only be able to put the verified logo next to videos that are cryptographically signed in the metadata as originating from the whitehouse (or probably better, some federal election authority who signs any campaign videos as certified/legitimate: in australia we have the AEC - australian electoral commission - a federal body that runs our federal elections and investigations election issues, etc)
now this of course wouldn’t work for sites outside of US control, but it would at least slow the flow of deepfakes on facebook, instagram, tiktok, the platform formerly known as twitter… assuming they implemented it, and assuming the govt enforced it
General_Effort@lemmy.world 10 months ago
For the average end-user, it would look like “https”. You would not have to know anything about the technical background. Your browser or other media player would display a little icon showing that the media is verified by some trusted institution and you could learn more with a click.
In practice, I see some challenges. You could already go to the source via https, EG whitehouse.gov, and verify it that way. An additional benefit exists only if you can verify media that have been re-uploaded elsewhere. Now the user needs to check that the media was not just signed by someone (EG whitehouse.gov.ru), but if it was really signed by the right institution.
TheKingBee@lemmy.world 10 months ago
As someone points out above, this just gives them the power to not authenticate real videos that make them look bad…
General_Effort@lemmy.world 10 months ago
Videos by third parties, like Trump’s pussy grabber clip, would obviously have to be signed by them. After having thought about it, I believe this is a non-starter.
It just won’t be as good as https. Such a signing scheme only makes sense if the media is shared away from the original website. That means you can’t just take a quick look at the address bar to make sure you are not getting phished. That doesn’t work if it could be any news agency. You have to make sure that the signer is really a trusted agency and not some scammy lookalike. That takes too much care for casual use, which defeats the purpose.
Also, news agencies don’t have much of an incentive to allow sharing their media. Any cryptographic signature would only make sense for them if directs users to their site, where they can make money. Maybe the potential for more clicks - basically a kind of clickable watermark on media - could make this take off.
dejected_warp_core@lemmy.world 10 months ago
I honestly feel strategies like this should be mitigated by technically savvy journalism, or even citizen journalism. 3rd parties can sign and redistribute media in the public domain, vouching for their origin. While that doesn’t cover all the unsigned copies in existence, it provides a foothold for more sophisticated verification mechanisms like a “tineye” style search for media origin.
Starbuck@lemmy.world 10 months ago
Adobe is actually one of the leading actors in this field, take a look at the Content Authenticity Initiative (contentauthenticity.org)
Like the other person said, it’s based on cryptographic hashing and signing. Basically the standard would embed metadata into the image.
Natanael@slrpnk.net 10 months ago
Not very well apparently
PhlubbaDubba@lemm.ee 10 months ago
Probably you’d notice a bit of extra time posting for the signature to be added, but that’s about it, the responsibility for verifying the signature would fall to the owners of the social media site and in the circumstances where someone asks for a verification, basically imagine it as a libel case on fast forward, you file a claim saying “I never said that”, they check signatures, they shrug and press the delete button and erase the post, crossposts, and if it’s really good screencap posts and those crossposts of the thing you did not say but is still being attributed falsely to your account or person.
It basically gives absolute control of a person’s own image and voice to themself, unless a piece of media is provable to have been made with that person’s consent, or by that person themself, it can be wiped from the internet no trouble.
Where it comes to second party posters, news agencies and such, it’d be more complicated but more or less the same, with the added step that a news agency may be required to provide some supporting evidence that what they said is not some kind of misrepresentation or such as the offended party filing the takedown might be trying to insist for the sake of their public image.
Of course there could still be a YouTube “Stats for Nerds”-esque addin to the options tab on a given post that allows you to sign-check it against the account it’s attributing something to, and a verified account system could be developed that adds a layer of signing that specifically identifies a published account, like say for prominent news reporters/politicians/cultural leaders/celebrities, that get into their own feed so you can look at them or not depending on how ya be feelin’ that particular scroll session.
Cocodapuf@lemmy.world 10 months ago
It needs some kind of handler, but we mostly have those in place. A web browser could be the handler for instance. A web browser has the green dot on the upper left, telling you a page is secure, that https is on and valid. This could work like that, the browser can verify the video and display a green or red dot in the corner, the user could just mouse over it/tap on it to see who it’s verified to be from. But it’s up to the user to mouse over it and check if it says whitehouse.gov or dr-evil-mwahahaha.biz
dejected_warp_core@lemmy.world 10 months ago
TL;DR: one day the user will see an overlay or notification that shows an image/movie is verified as from a known source. No extra software required.
Honestly, I can see this working great in future web browsers. Much like the padlock in the URL bar, we could see something on images that are verified. The image could display a padlock in the lower-left corner or something, along with the name of the source, demonstrating that it’s a securely verified asset. “Normal” images would be unaffected. The big problem is how to put something on the page that cannot be faked by other means.
It’s a little more complicated for software like phone apps like X or Facebook, but doable. The problem is that those products must choose to add this feature. Hopefully, losing reputation to being swamped with unverifiable media will be motivation enough to do so.
The underlying verification process is complex, but should be similar to existing technology (e.g. GPG). The key is that images and movies typically contain a “scratch pad” area in the file for miscellaneous stuff (metadata). This is where the image’s author can add a cryptographic signature for the file itself. The user would never even know it’s there.
pupbiru@aussie.zone 10 months ago
i wouldn’t say signature exactly, because that ensures that a video hasn’t been altered in any way: no re-encoded, resized, cropped, trimmed, etc… platforms almost always do some of these things to videos, even if it’s not noticeable to the end-user
there are perceptual hashes, but i’m not sure if they work in a way that covers all those things or if they’re secure hashes. i would assume not
perhaps platforms would read the metadata in a video for a signature and have to serve the video entirely unaltered if it’s there?
thantik@lemmy.world 10 months ago
You don’t need to bother with cryptographically verifying downstream videos, only the source video needs to be able to be cryptographically verified. That way you have an unedited, untampered cut that can be verified to be factually accurate to the broadcast.
pupbiru@aussie.zone 10 months ago
you don’t even need to cryptographically verify in that case because you already have a trusted authority: the whitehouse… of the video is on the whitehouse website, it’s trusted with no cryptography needed
the technical solutions only come into play when you’re trying to modify the video and still accurately show that it’s sourced from something verifiable
AbouBenAdhem@lemmy.world 10 months ago
Rather that using a hash of the video data, you could just include within the video the timestamp of when it was originally posted, encrypted with the White House’s private key.
Natanael@slrpnk.net 10 months ago
That doesn’t prove that the data outside the timestamp is unmodified
AbouBenAdhem@lemmy.world 10 months ago
It does if you can also verify the date of the file, because the modified file will be newer than the timestamp.
Natanael@slrpnk.net 10 months ago
Apple’s scrapped on-device CSAM scanning was based on perceptual hashes.
The first collision demo breaking them showed up in hours with images that looked glitched. After just a week the newest demos produced flawless images with collisions against known perceptual hash values.
In theory you could create some ML-ish compact learning algorithm and use the compressed model as a perceptual hash, but I’m not convinced this can be secure enough unless it’s allowed to be large enough, as in some % of the original’s file size.
pupbiru@aussie.zone 10 months ago
you can definitely produced perceptual hashes that collide, but really you’re not just talking about a collision, you’re talking about a collision that’s also useful in subverting an election, AND that’s been generated using ML which is something that’s still kinda shakey to start with
Natanael@slrpnk.net 10 months ago
Perceptual hash collision generators can take arbitrary images and tweak them in invisible ways to make them collide with whichever hash value you want.
mods_are_assholes@lemmy.world 10 months ago
Maybe deepfakes are enough of a scare that this becomes standard practice, and protects encryption from getting government backdoors.
RVGamer06@sh.itjust.works 10 months ago
Image
mods_are_assholes@lemmy.world 10 months ago
Hey, congresscritters didn’t give a shit about robocalls till they were the ones getting robocalled.
We had a do not call list within a year and a half.
That’s the secret, make it affect them personally.
Daft_ish@lemmy.world 10 months ago
Doesn’t that prove that government officials lack empathy? We see it again and again but still we keep putting these unfeeling bastards in charge.