4 ms·

iPhone lidar only works up to like 16 feet in the easiest lighting conditions (indoors) and may be functionally ineffective outdoors.

pveierland 12d ago
Still, that means that either the fake target scene and your screen presenting it would need to be outside of LiDAR sensor bounds, or you'd need to find a way to make the depth sensor data conform with your fake scene, both increasing the difficulty of producing a forgery.
- BugsJustFindMe 12d ago
  https://news.ycombinator.com/item?id=49721878 https://news.ycombinator.com/item?id=49721878 > increasing the difficulty of producing a forgery The problem with this thinking is twofold: 1) Whether it actually meaningfully increases the difficulty of a forgery remains to be seen. Despite their initial language about discerning real events, we see no details here about what scene information is used. 2) It increases the potential value of a forgery because now your forgery is attested by Apple. So it either makes it easier to defraud people or more worthwhile to put in the effort to defraud people or both. None of those outcomes are great.
- moffkalast 12d ago
  A sufficiently light absorbing material is indistinguishable from infinity to a lidar. Or simply add a mirror that redirects it sideways, those can't be detected either.
gruez 12d ago
So you need a big enough screen to cover the entire field of view at 16 ft? Sounds expensive
- BugsJustFindMe 12d ago
  Well, first, that's only expensive if you're poor. The world is absolutely full of people who can easily piss away your entire annual income throwing a house party. But I really mean that if the lidar barely works outdoors anyway then actually you don't need to be 16 feet away at all. Anyway, one may presume that they've thought about this.
  - somethinsfishy 12d ago
    Put some sugar on it. Please.
    - BugsJustFindMe 12d ago
      Def Leppard, is that you?
  - brookst 12d ago
    Thought about it and also are bright enough not to fall for the “if a single person dies wearing a seat belt, we should abandon seat belts because they do no good at all” fallacy. It’s almost certainly possible to fool v1 of this system, for some images, in some contexts. It would be shocking if the first implementation was completely perfect. But maybe it’s better than nothing?
    - BugsJustFindMe 12d ago
      > But maybe it’s better than nothing? I think this will depend on how it gets used. I can imagine numerous outcomes where it's in fact worse than nothing (significantly more effective blackmail, for instance).
      - brookst 11d ago
        I guess? The bailey version of that argument is that we should do away with the concept of truth altogether, because some truths are harmful.
    - akersten 12d ago
- nomel 12d ago
  Or, probably just some optics, like a slanted $9 IR mirror [1] in front of it, to direct the lidar to the sky/absorption box. Then you can point at the high res HDR TV that's probably already in your living room. [1] https://commonlands.com/products/ir-cut-filters-csp650?srsltid=AU7gw4X-pCzrQspQzH18g1_O281WPxL3N-zhy48Usxf-IMb8Ctbs45Bk https://commonlands.com/products/ir-cut-filters-csp650?srslt...

pveierland 12d ago

Still, that means that either the fake target scene and your screen presenting it would need to be outside of LiDAR sensor bounds, or you'd need to find a way to make the depth sensor data conform with your fake scene, both increasing the difficulty of producing a forgery.

BugsJustFindMe 12d ago
https://news.ycombinator.com/item?id=49721878 https://news.ycombinator.com/item?id=49721878 > increasing the difficulty of producing a forgery The problem with this thinking is twofold: 1) Whether it actually meaningfully increases the difficulty of a forgery remains to be seen. Despite their initial language about discerning real events, we see no details here about what scene information is used. 2) It increases the potential value of a forgery because now your forgery is attested by Apple. So it either makes it easier to defraud people or more worthwhile to put in the effort to defraud people or both. None of those outcomes are great.
moffkalast 12d ago
A sufficiently light absorbing material is indistinguishable from infinity to a lidar. Or simply add a mirror that redirects it sideways, those can't be detected either.

gruez 12d ago

So you need a big enough screen to cover the entire field of view at 16 ft? Sounds expensive

BugsJustFindMe 12d ago
Well, first, that's only expensive if you're poor. The world is absolutely full of people who can easily piss away your entire annual income throwing a house party. But I really mean that if the lidar barely works outdoors anyway then actually you don't need to be 16 feet away at all. Anyway, one may presume that they've thought about this.
- somethinsfishy 12d ago
  Put some sugar on it. Please.
  - BugsJustFindMe 12d ago
    Def Leppard, is that you?
- brookst 12d ago
  Thought about it and also are bright enough not to fall for the “if a single person dies wearing a seat belt, we should abandon seat belts because they do no good at all” fallacy. It’s almost certainly possible to fool v1 of this system, for some images, in some contexts. It would be shocking if the first implementation was completely perfect. But maybe it’s better than nothing?
  - BugsJustFindMe 12d ago
    > But maybe it’s better than nothing? I think this will depend on how it gets used. I can imagine numerous outcomes where it's in fact worse than nothing (significantly more effective blackmail, for instance).
    - brookst 11d ago
      I guess? The bailey version of that argument is that we should do away with the concept of truth altogether, because some truths are harmful.
  - akersten 12d ago
nomel 12d ago
Or, probably just some optics, like a slanted $9 IR mirror [1] in front of it, to direct the lidar to the sky/absorption box. Then you can point at the high res HDR TV that's probably already in your living room. [1] https://commonlands.com/products/ir-cut-filters-csp650?srsltid=AU7gw4X-pCzrQspQzH18g1_O281WPxL3N-zhy48Usxf-IMb8Ctbs45Bk https://commonlands.com/products/ir-cut-filters-csp650?srslt...