4 comments

  • treyd 3 minutes ago
    I don't understand why few people are pointing out the obvious vulnerability here that you can control the wires going into the photosensor controller and pretend that the photosensor is capturing whatever image you want. I imagine it's not exactly trivial to do this, but a grad student with an FPGA could probably figure it out.
  • fitzn 49 minutes ago
    Here's a toy for embedding small text into images steganographically: https://github.com/fitzn/atrium
  • xg15 42 minutes ago
    > For example, a screen attack still works: photograph a screen displaying an AI image and you get a signed photo of a fake. But it's always nice seeing big actors interested in addressing this problem.

    Yeah, very nice. So this whole idea basically doesn't work - but we get a new stealth way to embed metadata in an image that can be used for tracking...

    (And a new narrative why cameras need to have TPMs and locked-down firmware as well)

    • shagie 23 minutes ago
      Photos of photos has always been a problem.

      In days of old, a Polaroid photo was considered "proof of capture".

      I've got a Polaroid daylab 35 plus sitting in storage somewhere (https://www.instantoptions.com/wp/faqs/daylab/). You can project a slide through it onto Polaroid film, expose it, and have the image there.

      I was also able to find a company that did slide printing. It was possible to send them a digital image and they'd send you back a slide with that image... which I then used to make a Polaroid of that image.

      I had a classic 600 Polaroid photo of a UFO landing.

    • azatom 23 minutes ago
      That signature contains time and optionally gps coords, and taking photo of a screen is not simple. So overall does solve some problem

      ps:most important: cam/lens settings also in the digital sig, what for a screen is different

    • ChocolateGod 32 minutes ago
      Couldn't the camera encode information from the depth sensor and prevent this.
  • vzaliva 42 minutes ago
    I expect in the near future all digital cameras to digitally sign the images they take. Even before AI slop, it was useful to avoid manual alterations. AI makes it all too easy, so it makes sense.

    However, this will certify only the original image. I think the missing part of this is additional layers of certification which allow some image editing (e.g., rotating, contrast, etc.) yet clearly document that the image was modified and link to the original image ID. Kind of like a signed git log.

    • xg15 40 minutes ago
      EXIF data is stripped for a good reason - because it can be a privacy hazard. Suddenly this plays no role anymore?
      • stvltvs 25 minutes ago
        Signing the raw image data wouldn't require also signing the EXIF metadata. For privacy, you could later strip out everything except the raw image and the camera's signature and still prove that the image is unaltered.
      • doc_ick 31 minutes ago
        Ontop of this, including a photo edit history in a photo including the original photo would increase the size of a photo to be completely unusable or unshareable.
        • xg15 26 minutes ago
          I understood the GP so that only some unique ID or hash of the original image would be included, not the image itself. Basically like the commit chain of Git but without the actual content blobs.

          You could use this data to prove that image B is an edit of image A if you already have both A and B.

          I still think this is a bad idea, because this all requires the images to have some sort of ID - and that seems like a prime target for tracking.

    • teravor 7 minutes ago
      if such a method gains traction then so will the effort to bypass it. either by stealing private keys or just projecting light onto its sensor.
    • ranger_danger 28 minutes ago
      There will always be a way around it. There are even open-source alternative/hacked firmwares for professional DSLR cameras where tampering with the signing may be possible.

      And this still doesn't help any other kind of image e.g. screenshots, photo of a screen etc. that can make the camera signatures largely pointless depending on the context.

      • stvltvs 20 minutes ago
        The idea is to be able to prove that a photo you took was captured by a camera, not generated. That would be helpful in the context of a disputed news story, a court case, etc.

        Would that ever be relevant for a screenshot?