5 ms·
Fun tidbit: Three letter intelligence agencies have known about this attack vector since before this paper was published, and are worried it could be exploited
by tristanj 9y ago
Fun tidbit: Three letter intelligence agencies have known about this attack vector since before this paper was published, and are worried it could be exploited in the wild.
https://www.theguardian.com/world/2013/aug/20/nsa-snowden-files-drives-destroyed-london https://www.theguardian.com/world/2013/aug/20/nsa-snowden-fi...
[British government officials] expressed fears that foreign governments, in particular Russia or China, could hack into the Guardian's IT network. But the Guardian explained the security surrounding the documents, which were held in isolation and not stored on any Guardian system.
However, in a subsequent meeting, an intelligence agency expert argued that the material was still vulnerable. He said by way of example that if there was a plastic cup in the room where the work was being carried out foreign agents could train a laser on it to pick up the vibrations of what was being said. Vibrations on windows could similarly be monitored remotely by laser.
- Judgmentality 9y agoI've actually done this in a lab with a laser - it's a fun trick. What the original article talks about though is passively measuring sound from objects using a camera - no laser. Although they're measuring the same thing (physical vibrations of objects) the way they're doing it is actually quite different.
- petertodd 9y agoA friend of mine used that technique while working in an entomology lab studying the mating habits of cockroaches. They were trying to figure out what kinds of vocalizations the cockroaches were making while mating, and bouncing a laser off their shell was by far the easiest way to record those very quiet sounds. It's been a few years, but I think this was the manufacturer: https://www.polytec.com/us/vibrometry/products/ https://www.polytec.com/us/vibrometry/products/ I wouldn't be surprised if the non-laser techniques eventually also show up as off-the-shelf products too, simply to reduce costs - a simple camera could be cheaper than a laser, and might have advantages in being able to record sounds off multiple points at once.
- slazaro 9y agoAlso, I think a big advantage for the camera-based solutions is that they're totally passive, while laser-based need to interact with the object.
- Zigurd 9y agoTo make a camera-based solution practical, it seems like one would neeed a specialized camera, for modest resolution, but very high frame rate. Without enough frame-rate, you can't capture high frequencies. Even if speech could be discerned from a spectrum that rolls off at 300hz, well under the peak energy of a typical human's speech, you would still need many hundreds of frames per second.
- fisherjeff 9y agoIf you watch the video at the end, you'll see that they actually exploit the fact that CMOS pixels are read out sequentially and use the data from each row to extract surprisingly decent high frequency data from even 60 Hz video!
- mikeash 9y agoThey article says they were able to use the rolling shutter on standard cameras to extract data at a much higher frequency than the nominal framerate would allow.
- regularfry 9y agoThe article talks about this. The rolling-shutter effect means that you can get information out at higher than frame rate.
- kriro 9y agoPretty cool idea but I would be a little worried that the laser itself could influence the mating habits due to heat/distraction etc.
- pilsetnieks 9y agoThe laser thing has been around for a while and is quite well known. The innovation here is that they found a way to do it without any lasers and possibly even with consumer cameras.