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that is absolutely never going to be workable because you can just film another video being played back.

by throwaway2048 9y ago

nine_k 9y ago
I can imagine watermarking at the light sensor level. It would need some very special provisions for compression, though.
- striking 9y ago
  Well, but then you'd have to trust the light sensor manufacturer to provide secure keys. Remember when the NSA hacked into Gemalto and had a chance to steal its SIM card keys? However, that's still interesting; isn't it possible that each light sensor has certain watermark-like characteristics arising from the manufacturing process?
  - c22 9y ago
    Yes, fingerprinting of digital cameras has been a thing for at least a decade [https://www.eurekalert.org/pub_releases/2006-04/bu-bur041806.php https://www.eurekalert.org/pub_releases/2006-04/bu-bur041806...]
- sametmax 9y ago
  Problem is, this way journalists won't have anonymous sources anymore and you will be able to track any citizen filming power abuses.
beisner 9y ago
I mean, there are all kinds of ways to bound uncertainty. You’re right, you could film another camera, but that could be addressed separately. Digital signing would only prove that a video came directly from a particular camera’s sensors. To assert the veracity of a video, you’d then have to prove that particular camera was at the scene, and the light coming into the lens was authentic. Most court footage is incidental, not intentional, so the sort of doctoring you describe is unlikely in a majority of cases. Where it is likely, different measures could be taken to bound uncertainty. Separately, generating false images or videos for libel purposes would become more difficult; if a camera that has never been owned by a person is used to produce a signed video that is pornographic in nature, the authenticity of that video is immediately suspect. It would take a much more sophisticated attack to produce a mathematically convincing fake video.
- throwaway2048 9y ago
  if you are worried about somebody actively faking footage, and are willing to go to such drastic DRM measures to prevent it, you need to explain how it is actually going to solve the problem, not just handwave.

that is absolutely never going to be workable because you can just film another video being played back.

I can imagine watermarking at the light sensor level. It would need some very special provisions for compression, though.

striking 9y ago
Well, but then you'd have to trust the light sensor manufacturer to provide secure keys. Remember when the NSA hacked into Gemalto and had a chance to steal its SIM card keys? However, that's still interesting; isn't it possible that each light sensor has certain watermark-like characteristics arising from the manufacturing process?
- c22 9y ago
  Yes, fingerprinting of digital cameras has been a thing for at least a decade [https://www.eurekalert.org/pub_releases/2006-04/bu-bur041806.php https://www.eurekalert.org/pub_releases/2006-04/bu-bur041806...]
sametmax 9y ago
Problem is, this way journalists won't have anonymous sources anymore and you will be able to track any citizen filming power abuses.

beisner 9y ago

I mean, there are all kinds of ways to bound uncertainty. You’re right, you could film another camera, but that could be addressed separately. Digital signing would only prove that a video came directly from a particular camera’s sensors. To assert the veracity of a video, you’d then have to prove that particular camera was at the scene, and the light coming into the lens was authentic. Most court footage is incidental, not intentional, so the sort of doctoring you describe is unlikely in a majority of cases. Where it is likely, different measures could be taken to bound uncertainty. Separately, generating false images or videos for libel purposes would become more difficult; if a camera that has never been owned by a person is used to produce a signed video that is pornographic in nature, the authenticity of that video is immediately suspect. It would take a much more sophisticated attack to produce a mathematically convincing fake video.

throwaway2048 9y ago
if you are worried about somebody actively faking footage, and are willing to go to such drastic DRM measures to prevent it, you need to explain how it is actually going to solve the problem, not just handwave.