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I work at Axis, which makes surveillance cameras.[0] This comment is my own, and is not on behalf of the company. I'm using a throwaway account because I'd rath

by throw9871928 4y ago

I work at Axis, which makes surveillance cameras.[0] This comment is my own, and is not on behalf of the company. I'm using a throwaway account because I'd rather not be identified (and because surveillance is quite controversial here). Axis has developed a way to cryptographically sign video, using TPMs (Trusted Platform Module) built into the cameras and embedding the signature into the h.264 stream.[1] The video can be verified on playback using an open-source video player.[2] I hope this sort of video signing will be mainstream in all cameras in the future (i.e. cellphones etc), as it will pretty much solve the trust issues deep fakes are causing. [0] https://www.axis.com/ https://www.axis.com/ [1] https://www.axis.com/newsroom/article/trust-signed-video https://www.axis.com/newsroom/article/trust-signed-video [2] https://www.axis.com/en-gb/newsroom/press-release/axis-communications-launches-open-source-project-for-video-authentication-to-ensure-the-integrity-of-surveillance-video https://www.axis.com/en-gb/newsroom/press-release/axis-commu...

Tepix 4y ago
> it will pretty much solve the trust issues I'm not so sure. How will you verify a signature if you see a video on TV or on social media? Do you believe these devices are 100% secure and the keys will never be extracted?
- throw9871928 4y ago
  Nothing is 100% secure, but the point of using a TPM is to prevent extraction of the keys.
  - Diggsey 4y ago
    TPMs are great at preventing extraction of keys via the exploitation of software bugs. They are not so good at preventing extraction if you have physical access to the machine, and especially not if you don't need the machine to survive intact, and can afford to destroy as many machines as you need to get the keys out...
  - Tepix 4y ago
    I agree that it's better than nothing. Sooner or later deepfakes will be pretty much perfect and detection will be more or less impossible.
- Workaccount2 4y ago
  It will be 6 months before hardware bypass devices show up on alibaba.
jonathanstrange 4y ago
It shouldn't be too hard to film a deepfake movie from a screen or projection that don't make it obvious it was filmed. That way, the cryptographic signature will even lend extra authenticity to the deepfake!
- galangalalgol 4y ago
  A screen with double the resolution and twice the framrate should be indistinguishable. Moreover if you pop the case on the camera and replace the sensor with something fed by display port (probably need an fpga to convert display port to lvds, spi,ic2 or whatever those sensors use, at speed) that should work too.
  - throw9871928 4y ago
    This is still a lot harder than just using the deepfake application in the OP. But I’ll admit the arms race might not be over yet.
    - galangalalgol 4y ago
      You can raise the bar a bit. No one checks to see if a $5 bill is fake. There is no real upper limit on what the payout for a deepfake could be. TPM isnt going to save facial recognition ID like the IRS from being obsoleted by deepfakes. But, for things that go to trial a TPM dashcam with tamper evident packaging (that can be inspected during trial) is probably good enough for small claims court. You could add GPS spoof detection, put as much as you can on the tpm chip (like the accelerometer), and sign all sorts of available data along with the video, but that will up the unit price a lot, and for the kind of fraudulent payouts you'd be trying to stop, you wouldn't make it enough harder to keep it from being cost effective for the fakers.
  - mgdlbp 4y ago
    Not if the camera includes metadata like focus, shutter speed, accelerometer, GPS, etc. I don't really know, but I imagine the hardware security required wouldn't be too far from what's common now. Cameras are already unrepairable, so I suppose the arguments would have to be more from the privacy and who-controls-the-chipmakers perspectives.
jacquesm 4y ago
That will just move the hack one level further down and will create even more confusion because then you'll have a 'properly signed video stream' as a kind of certificate that the video wasn't manipulated. But you don't really know that, because the sensor input itself could be computer generated and I can think off the bat of at least two ways in which I could do just that.
- pbhjpbhj 4y ago
  Isn't the point to prove physical access to the camera. As in, this stream originated at this TPM which was sold as part of this camera. So, the best you get is that the stream shows it wasn't produced with access to a particular camera. Then impersonating a YouTuber, say, requires access to their physical camera.
  - jacquesm 4y ago
    > Isn't the point to prove physical access to the camera. Yes. But since you can't really prove who had and who did not have physical access to the camera (what are you going to use, video evidence ;) ) that carries little weight. Let's say we're talking about a death penalty or a multi billion $ lawsuit, the stakes would be so high that to rely on something as trivial as a signature on a video stream would be way too risky because of the consequences. Which expert would sign on the dotted line to the statement that 'the equipment has not been accessed by someone who wasn't authorized to do so'? And that's before we get into the question of whether this camera really is the only way that this particular video could be generated (can duplicates of the TPM be made by the manufacturer?), you'd have to do a lot of work to make guarantees that would stand the test of time. All it takes is one 'DVD Jon' and you can kiss your carefully constructed scheme goodbye. Finally, the whole chain of that video would have to preserve the signatures, which in a world that tries to balance privacy with other concerns may not be feasible and in fact could well have downsides all its own. Personally I would much rather see the level of skepticism against all kinds of digital evidence go up than to see the trust go up due to supposedly magic signatures and other tricks to pretend that we have a perfect lock on this stuff. Every time we believe we do someone comes along that proves us wrong, usually after the damage is done. See also: fingerprints, face recognition, DNA evidence, lie detectors, bomb detectors and so on.
tinus_hn 4y ago
The surveillance states wet dream, where you can just look up who took that ‘unfair’ video of your agent breaking the rules.
- colejohnson66 4y ago
  You're being uncharitable. I read it as a way for a person to prove they took the video, not as a database of person<->signing key. In other words, the government would only be able to see that video 123 was signed by signature 456. It would be up to the poster to prove they own the camera that produced signature 456.
  - tinus_hn 4y ago
    So as long as you never post any video you made with that camera on any account that is not anonymous, you’re safe. In other words, completely impractical. This is exactly why all these identifiers and all this tracking are harmful: you can never be anonymous, there’s always someone watching who can couple everything you do to your identity. And it happens with you knowing as little about it as possible.
driverdan 4y ago
I don't see how that would be useful here. I'm not giving out info about my webcam to anyone. There would be no way to verify the signature.
- rockemsockem 4y ago
  Manufacturer signature, not your signature.
npteljes 4y ago
>it will pretty much solve the trust issues deep fakes are causing. It's a nice piece of tech, I can see it being used in court for example, to strengthen the claim that a video is not a deepfake. However, that's not "the" problem with deepfakes. Propaganda of all sorts have demonstrated that "Falsehood flies, and the Truth comes limping after it". As in, with the proper deepfakes, you can do massive damage via social media for example. People re-share without validation all the time, and the existence of deepfakes add fuel to this fire. And I think that we can't do anything about either.
kube-system 4y ago
That will help someone determine that a fake video didn't come from their own camera. But most videos where we're worried about deep fakes are videos that come from other people's cameras, where we don't know which signature should be valid, nor whether it should have a signature.
- rockemsockem 4y ago
  I believe they're saying that the manufacturer will sign the video, not the filmer. Those signatures can then be validated by platforms that the video is uploaded to. The signature isn't supposed to say "this video came from person X" it's supposed to say "this video in fact came from the real world".
  - kube-system 4y ago
    But there are many manufacturers of cameras. How do I know that a particular clip should even be signed? Signatures don’t change the provenance problem.
    - rockemsockem 4y ago
      It seems like the goal would be to make this ubiquitous enough that eventually you'll expect all clips to be signed, although this would of course take quite a long time to achieve, which would indeed undermine the authenticity guarantees a system like this could provide. It seems like official channels like CSPAN, white house press briefings, and other world governments could get immediate benefit by applying these methods to all of their official communiques.
rockemsockem 4y ago
That's really cool! I've been waiting for tech like this to finally come to light. Honestly expected either Google or Apple to lead the way on it. Have you all worked with the content authenticity initiative at all? It seems like they're looking at ways to develop standards around tech like this to ensure interoperability in the future. https://contentauthenticity.org/ https://contentauthenticity.org/
culopatin 4y ago
Hey, off topic but I love your cameras and the attention to detail you put in them, especially in regards to what helps the tech install them.

Tepix 4y ago

> it will pretty much solve the trust issues I'm not so sure. How will you verify a signature if you see a video on TV or on social media? Do you believe these devices are 100% secure and the keys will never be extracted?

throw9871928 4y ago
Nothing is 100% secure, but the point of using a TPM is to prevent extraction of the keys.
- Diggsey 4y ago
  TPMs are great at preventing extraction of keys via the exploitation of software bugs. They are not so good at preventing extraction if you have physical access to the machine, and especially not if you don't need the machine to survive intact, and can afford to destroy as many machines as you need to get the keys out...
- Tepix 4y ago
  I agree that it's better than nothing. Sooner or later deepfakes will be pretty much perfect and detection will be more or less impossible.
Workaccount2 4y ago
It will be 6 months before hardware bypass devices show up on alibaba.

jonathanstrange 4y ago

It shouldn't be too hard to film a deepfake movie from a screen or projection that don't make it obvious it was filmed. That way, the cryptographic signature will even lend extra authenticity to the deepfake!

galangalalgol 4y ago
A screen with double the resolution and twice the framrate should be indistinguishable. Moreover if you pop the case on the camera and replace the sensor with something fed by display port (probably need an fpga to convert display port to lvds, spi,ic2 or whatever those sensors use, at speed) that should work too.
- throw9871928 4y ago
  This is still a lot harder than just using the deepfake application in the OP. But I’ll admit the arms race might not be over yet.
  - galangalalgol 4y ago
    You can raise the bar a bit. No one checks to see if a $5 bill is fake. There is no real upper limit on what the payout for a deepfake could be. TPM isnt going to save facial recognition ID like the IRS from being obsoleted by deepfakes. But, for things that go to trial a TPM dashcam with tamper evident packaging (that can be inspected during trial) is probably good enough for small claims court. You could add GPS spoof detection, put as much as you can on the tpm chip (like the accelerometer), and sign all sorts of available data along with the video, but that will up the unit price a lot, and for the kind of fraudulent payouts you'd be trying to stop, you wouldn't make it enough harder to keep it from being cost effective for the fakers.
- mgdlbp 4y ago
  Not if the camera includes metadata like focus, shutter speed, accelerometer, GPS, etc. I don't really know, but I imagine the hardware security required wouldn't be too far from what's common now. Cameras are already unrepairable, so I suppose the arguments would have to be more from the privacy and who-controls-the-chipmakers perspectives.

jacquesm 4y ago

That will just move the hack one level further down and will create even more confusion because then you'll have a 'properly signed video stream' as a kind of certificate that the video wasn't manipulated. But you don't really know that, because the sensor input itself could be computer generated and I can think off the bat of at least two ways in which I could do just that.

pbhjpbhj 4y ago
Isn't the point to prove physical access to the camera. As in, this stream originated at this TPM which was sold as part of this camera. So, the best you get is that the stream shows it wasn't produced with access to a particular camera. Then impersonating a YouTuber, say, requires access to their physical camera.
- jacquesm 4y ago
  > Isn't the point to prove physical access to the camera. Yes. But since you can't really prove who had and who did not have physical access to the camera (what are you going to use, video evidence ;) ) that carries little weight. Let's say we're talking about a death penalty or a multi billion $ lawsuit, the stakes would be so high that to rely on something as trivial as a signature on a video stream would be way too risky because of the consequences. Which expert would sign on the dotted line to the statement that 'the equipment has not been accessed by someone who wasn't authorized to do so'? And that's before we get into the question of whether this camera really is the only way that this particular video could be generated (can duplicates of the TPM be made by the manufacturer?), you'd have to do a lot of work to make guarantees that would stand the test of time. All it takes is one 'DVD Jon' and you can kiss your carefully constructed scheme goodbye. Finally, the whole chain of that video would have to preserve the signatures, which in a world that tries to balance privacy with other concerns may not be feasible and in fact could well have downsides all its own. Personally I would much rather see the level of skepticism against all kinds of digital evidence go up than to see the trust go up due to supposedly magic signatures and other tricks to pretend that we have a perfect lock on this stuff. Every time we believe we do someone comes along that proves us wrong, usually after the damage is done. See also: fingerprints, face recognition, DNA evidence, lie detectors, bomb detectors and so on.

tinus_hn 4y ago

The surveillance states wet dream, where you can just look up who took that ‘unfair’ video of your agent breaking the rules.

colejohnson66 4y ago
You're being uncharitable. I read it as a way for a person to prove they took the video, not as a database of person<->signing key. In other words, the government would only be able to see that video 123 was signed by signature 456. It would be up to the poster to prove they own the camera that produced signature 456.
- tinus_hn 4y ago
  So as long as you never post any video you made with that camera on any account that is not anonymous, you’re safe. In other words, completely impractical. This is exactly why all these identifiers and all this tracking are harmful: you can never be anonymous, there’s always someone watching who can couple everything you do to your identity. And it happens with you knowing as little about it as possible.

driverdan 4y ago

I don't see how that would be useful here. I'm not giving out info about my webcam to anyone. There would be no way to verify the signature.

rockemsockem 4y ago
Manufacturer signature, not your signature.

npteljes 4y ago

>it will pretty much solve the trust issues deep fakes are causing. It's a nice piece of tech, I can see it being used in court for example, to strengthen the claim that a video is not a deepfake. However, that's not "the" problem with deepfakes. Propaganda of all sorts have demonstrated that "Falsehood flies, and the Truth comes limping after it". As in, with the proper deepfakes, you can do massive damage via social media for example. People re-share without validation all the time, and the existence of deepfakes add fuel to this fire. And I think that we can't do anything about either.

kube-system 4y ago

That will help someone determine that a fake video didn't come from their own camera. But most videos where we're worried about deep fakes are videos that come from other people's cameras, where we don't know which signature should be valid, nor whether it should have a signature.

rockemsockem 4y ago
I believe they're saying that the manufacturer will sign the video, not the filmer. Those signatures can then be validated by platforms that the video is uploaded to. The signature isn't supposed to say "this video came from person X" it's supposed to say "this video in fact came from the real world".
- kube-system 4y ago
  But there are many manufacturers of cameras. How do I know that a particular clip should even be signed? Signatures don’t change the provenance problem.
  - rockemsockem 4y ago
    It seems like the goal would be to make this ubiquitous enough that eventually you'll expect all clips to be signed, although this would of course take quite a long time to achieve, which would indeed undermine the authenticity guarantees a system like this could provide. It seems like official channels like CSPAN, white house press briefings, and other world governments could get immediate benefit by applying these methods to all of their official communiques.

rockemsockem 4y ago

That's really cool! I've been waiting for tech like this to finally come to light. Honestly expected either Google or Apple to lead the way on it. Have you all worked with the content authenticity initiative at all? It seems like they're looking at ways to develop standards around tech like this to ensure interoperability in the future. https://contentauthenticity.org/ https://contentauthenticity.org/

culopatin 4y ago

Hey, off topic but I love your cameras and the attention to detail you put in them, especially in regards to what helps the tech install them.