Picture this: when something takes a photo/video, a phone, a cctv camera, a DSLR, whatever, if it has internet access, it can hash the media it took, and store the hash+timestamp on a blockchain.
For reference, if it’s SHA256 + timestamp, thats like 35 bytes, or 35 terabytes for 1 trillion records. And there’s no ‘leak’ of the image itself.
This wouldn’t prove a particular video is/isn’t fake, but it would prove when it’s taken (or at least give a bound for when it was uploaded). And this is extremely useful to courts; say a video ends up being evidence. If you can tie it to the exact time of the crime, in many scenarios, the maker wouldn’t know to fake it in that moment. It’s impossible to edit a video/photo without changing its hash. Even police wouldn’t be able to fake it.
This is a rare useful (and frugal/practical) niche for blockchain. Immutable verification is a core principle.
To add on this, if the timetamp says 3:30 PM January 1, then all you need is the camera-person to testify that their camera is in their posession at the 3:30 PM on January 1, they recorded the video on scene, and that nobody else has touched/tampered with it. Then if the camera-person is unrelated to either party of a court case, then its very solid evidence, there’s no motive to fake it. More reliable than the camera-person’s own eyewitness testimony (since cameras don’t “misremember an event”)
But the credibility of the video would still be tied to the camera-person’s own credibility. If, for example, the camera-person was a conartist, then the validity of the video they supposedly recorded could be called into question.
And if the camera-person claims a whole separate event than what the camera recorded, then there might be forensics done on the camera to see if it was possibly hacked (as in, the hacker using “AI” to generate a fake sequence of events real-time then have the camera timestamp it to the internet).
This is a rare useful (and frugal/practical) niche for blockchain. Immutable verification is a core principle.
You’re right on everything else, but this is just no. You never need blockchain.
One just need someone who makes it credible that the hash and timestamp were not tampered with. Even posting the hash on Reddit would do it for most people. Reddit isn’t going to commit fraud for some random person. And that random person is probably not able to hack the database undetected.
Recomputing lots of hashes isn’t difficult. A blockchain doesn’t add any trustworthiness on its own.
One just need someone who makes it credible that the hash and timestamp were not tampered with.
This is the problem blockchain solves. That need for someone trustworthy disappears.
Even posting the hash on Reddit would do it for most people.
What? People can edit their own posts. Admins can edit other people’s posts. Anyone who thinks reddit is immutable is an idiot.
Reddit isn’t going to commit fraud for some random person.
Spez has already edited posts. Pay people enough and they will happily edit a database.
And that random person is probably not able to hack the database undetected.
Already happened. But also the user can “hack” their own entry.
What’s also missing is chronology. Blockchain fixes not only the document contents but also puts a minimum on the age. Also if the hash is signed then authorship can be attributed.
Recomputing lots of hashes isn’t difficult.
Yes it is. That’s whole reason blockchain works.
A blockchain doesn’t add any trustworthiness on its own.
The contents of a document can’t be trusted, but anything a blockchain (internally) verifies can be.
The device hashes the video (trivial on any CPU capable enough to handle media) and uploads that hash, a simple blockchain network (or some sufficient existing blockchain) ingests it and sets the timestamp, then it’s stored publicly, unencrypted, but set in stone.
Now that I think about it, this would work for any file (like documents) or indeed anything hashable. It’s simply a public ledger of hash + timestamp pairs to prove “a file with this hash existed at this time,” and there’s no need to encrypt any of it.
The blockchain sets the timestamp at the moment it’s added. All the ‘user’ can do is upload a hash.
Other than that, it doesn’t matter. It just a table of hashes + dates, and hash tells you nothing without the associated file. Fake media could be hashed, but if a timestamp can’t ‘verify’ the media in question for a particular situation, then it wouldn’t matter to a court anyway.
I guess one particular attack vector would be orgs flooding the system, unfortunately, and that would be difficult to work around.
If the timestamp can’t ‘prove’ its authenticity (like placing the video chronologically before anyone would know what slop to make), then it’s useless as evidence in court, even if the video is real.
I’ve entertained this concept before, but it presents issues. What if a piece of evidence needs to be edited? To protect someone’s identity (say an SA victim) or even just to cut an originally 1 hour stretch of security camera footage to the relevant 5 minutes.
There are plenty of legitimate reasons for editing photos or videos, even when being used as evidence. And I’m sure there’s ways around this using trusted chain of custody methods.
But I’ve seen this “just hash it and store the hash in an immutable, publicly verifiable manner (the actual use case for blockchain)” brought up before for this and stuff like governments signing recordings of their officials, and every time I have to point out that it ignores relevant key use cases.
I’m sure there’s ways to make this concept work, it isn’t a bad idea, but it’s never going to be quite so simple.
Yeah, though that particular complication is chain-of-custody like anything else, like you said. At some point the court has to trust evidence processing.
If (say) the defense wants to verify, they can ask the judge to scrub through original footage. This feels like a thing that could be smoothed out over time.
…But what worries me most is the ease of ‘spamming the system’. Say someone wanted to commit a crime pre-emptively, in front of devices doing this automatically; they’d have incentive to pay to flood the blockchain with random data. And if you introduce a small cyptocoin cost to uploading, well, that’s a whole can of worms you’ve opened there.
Picture this: when something takes a photo/video, a phone, a cctv camera, a DSLR, whatever, if it has internet access, it can hash the media it took, and store the hash+timestamp on a blockchain.
For reference, if it’s SHA256 + timestamp, thats like 35 bytes, or 35 terabytes for 1 trillion records. And there’s no ‘leak’ of the image itself.
This wouldn’t prove a particular video is/isn’t fake, but it would prove when it’s taken (or at least give a bound for when it was uploaded). And this is extremely useful to courts; say a video ends up being evidence. If you can tie it to the exact time of the crime, in many scenarios, the maker wouldn’t know to fake it in that moment. It’s impossible to edit a video/photo without changing its hash. Even police wouldn’t be able to fake it.
This is a rare useful (and frugal/practical) niche for blockchain. Immutable verification is a core principle.
To add on this, if the timetamp says 3:30 PM January 1, then all you need is the camera-person to testify that their camera is in their posession at the 3:30 PM on January 1, they recorded the video on scene, and that nobody else has touched/tampered with it. Then if the camera-person is unrelated to either party of a court case, then its very solid evidence, there’s no motive to fake it. More reliable than the camera-person’s own eyewitness testimony (since cameras don’t “misremember an event”)
But the credibility of the video would still be tied to the camera-person’s own credibility. If, for example, the camera-person was a conartist, then the validity of the video they supposedly recorded could be called into question.
And if the camera-person claims a whole separate event than what the camera recorded, then there might be forensics done on the camera to see if it was possibly hacked (as in, the hacker using “AI” to generate a fake sequence of events real-time then have the camera timestamp it to the internet).
You’re right on everything else, but this is just no. You never need blockchain.
One just need someone who makes it credible that the hash and timestamp were not tampered with. Even posting the hash on Reddit would do it for most people. Reddit isn’t going to commit fraud for some random person. And that random person is probably not able to hack the database undetected.
Recomputing lots of hashes isn’t difficult. A blockchain doesn’t add any trustworthiness on its own.
I suppose not. Blockchain’s a convenient system for this, but some other party ‘good enough for court’ would do, yes.
I was thinking of software ‘standard’ enough to centralize it, enough to incentivize has uploading being built into cameras and such as a feature.
This is the problem blockchain solves. That need for someone trustworthy disappears.
What? People can edit their own posts. Admins can edit other people’s posts. Anyone who thinks reddit is immutable is an idiot.
Spez has already edited posts. Pay people enough and they will happily edit a database.
Already happened. But also the user can “hack” their own entry.
What’s also missing is chronology. Blockchain fixes not only the document contents but also puts a minimum on the age. Also if the hash is signed then authorship can be attributed.
Yes it is. That’s whole reason blockchain works.
The contents of a document can’t be trusted, but anything a blockchain (internally) verifies can be.
This is sort of thing I’d hoped TPM would be used for, rather than being used to prevent running an alternative OS.
I don’t see what TPM’s needed for.
The device hashes the video (trivial on any CPU capable enough to handle media) and uploads that hash, a simple blockchain network (or some sufficient existing blockchain) ingests it and sets the timestamp, then it’s stored publicly, unencrypted, but set in stone.
Now that I think about it, this would work for any file (like documents) or indeed anything hashable. It’s simply a public ledger of hash + timestamp pairs to prove “a file with this hash existed at this time,” and there’s no need to encrypt any of it.
This sounds like the timestamping servers I’ve used on software builds. There are very few trusted ones and they get quite overloaded.
…and all they really prove is that a file had a certain hash at a certain time.
What ensures that only valid stuff gets pushed in the first place?
The blockchain sets the timestamp at the moment it’s added. All the ‘user’ can do is upload a hash.
Other than that, it doesn’t matter. It just a table of hashes + dates, and hash tells you nothing without the associated file. Fake media could be hashed, but if a timestamp can’t ‘verify’ the media in question for a particular situation, then it wouldn’t matter to a court anyway.
I guess one particular attack vector would be orgs flooding the system, unfortunately, and that would be difficult to work around.
What guarantees that what was uploaded in the first place wasn’t deepfake slop?
Doesn’t matter.
If the timestamp can’t ‘prove’ its authenticity (like placing the video chronologically before anyone would know what slop to make), then it’s useless as evidence in court, even if the video is real.
I’ve entertained this concept before, but it presents issues. What if a piece of evidence needs to be edited? To protect someone’s identity (say an SA victim) or even just to cut an originally 1 hour stretch of security camera footage to the relevant 5 minutes.
There are plenty of legitimate reasons for editing photos or videos, even when being used as evidence. And I’m sure there’s ways around this using trusted chain of custody methods.
But I’ve seen this “just hash it and store the hash in an immutable, publicly verifiable manner (the actual use case for blockchain)” brought up before for this and stuff like governments signing recordings of their officials, and every time I have to point out that it ignores relevant key use cases.
I’m sure there’s ways to make this concept work, it isn’t a bad idea, but it’s never going to be quite so simple.
Yeah, though that particular complication is chain-of-custody like anything else, like you said. At some point the court has to trust evidence processing.
If (say) the defense wants to verify, they can ask the judge to scrub through original footage. This feels like a thing that could be smoothed out over time.
…But what worries me most is the ease of ‘spamming the system’. Say someone wanted to commit a crime pre-emptively, in front of devices doing this automatically; they’d have incentive to pay to flood the blockchain with random data. And if you introduce a small cyptocoin cost to uploading, well, that’s a whole can of worms you’ve opened there.