26 ms·
Spies can eavesdrop by watching a light bulb's vibrations
- kanobo 6y agoTomorrow's news: Privacy Lightbulbs that vibrate pre-recorded messages to throw these pesky spies off their trail is invented.
- turbonaut 6y agoWhilst the suggestion is clearly not serious, having pre-recorded or even repeated random noise is akin to re-using a one time pad. Continued ‘listening’ - even long after the relevant conversation - could first be used to extract the fake noise and then from this the signal.
- kanobo 6y agoI'm going to put on my pop-science-fiction hat on and revise the Privacy Bulb to include a geiger–müller vibrating tube and a dollop of uranium for random vibrations. I was a fan of spy vs. spy as a child and I am full of bad ideas right now.
- kerkeslager 6y agoYeah. You can't just produce random white sound[1] to cover the signal either, because speech has enough redundancy to still communicate over a static-y soundscape. The term here is that white noise lacks "diffusion"--analogous to the ECB vulnerability (see the picture of the encrypted Linux penguin image on this page[2]). I can't think of a good way to provide diffusion for sound--a better cover might be to provide alternate signals, i.e. a few layers of random human sounds spoken in a deepfake-d version of the voice of the person speaking. I'm skeptical even this wouldn't have vulnerabilities however, as history has shown us that cryptography which has not been formally proven is often broken. [1] I'm using the word "sound" here to differentiate the noise in the auditory sense from noise in the "signal versus noise" sense. [2] https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#ECB https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation...
- kanobo 6y agoWould it be possible to use the tech in noise-cancelling headphones and put a tiny speaker that phase-cancels audio it hears to solve this issue? I'm asking as someone who knows very little about this.
- kerkeslager 6y agoWell, it's definitely possible to do that but I'll make no claim that it would actually provide security. There's definitely some bleed-through with noise canceling (i.e. the beginning of sounds don't get canceled because the noise-canceling has a "reaction time"). It's probably better than nothing, but I would guess that a sophisticated-enough attacker could get around it. Again, I have no proof of concept here, so take with a grain of salt.
- dasudasu 6y agoThen you can hijack the noise canceling device and obtain the original signal. Also the canceling effect is likely never perfect, so there would still remain part of it going through.
- deleted 6y ago[deleted]
- matham 6y agoWhat if you use one random source to contentiously change the white noise parameters (mean, std). E.g. use something like a illuminated disco ball that continuously randomly changes the source light angle and intensity.
- kerkeslager 6y agoI think it would be very difficult to escape from diffusion problems.
- SilasX 6y agoSince you mention it, I got to thinking about whether we can have a microphone equivalent to the physical covers for webcams -- that is, a physical means that ensures the device can't detect anything usable, even if an attacker was able to turn it on without you knowing. Something like, a vibrating module that you don't really notice but which clouds out any sounds the microphone would pick up (or, to go your route, injects fake audio). You turn it on when you want to be sure the microphone isn't listening, just like you can cover the webcam.
- kanobo 6y agoSome offices employ white noise privacy machines, you can find them on amazon. And the Japanese have the Sound Princess for flush noise privacy at the toilet. I have yet to find a product where you don't notice that it's on though, would be a great invention if possible.
- spockz 6y agoOr you could turn on the shower and faucets in the bathroom and talk there. Or does that only work in the movies?
- briandear 6y agoIt does work, but you can have filters that can remove that noise electronically enough to get some actual voice signal. Faucets along with whispering directly in the ear would work. But a better choice is to simply write on a piece of paper instead of talking.
- plutonic 6y agoYou mean something like this [0]? You could use this to trick your computer/phone into using the audio jack for its microphone, but since the mic-lock passes no usable signal, you'll be better protected. It doesn't otherwise incapacitate the internal microphone, though. [0] https://www.amazon.com/Mic-Lock-Microphone-Blocker-Pack-Surveillance/dp/B07C6LMSJ3/ https://www.amazon.com/Mic-Lock-Microphone-Blocker-Pack-Surv...
- hinkley 6y agoWe've known each other, for so long...
- deleted 6y ago[deleted]
- ravenstine 6y agoOne way you can do this without another light source is to bounce a laser beam off a window or other things that are reflective. In fact, the same principle can be achieved with radio. The Russians once planted a device in a wooden seal they gave to a US ambassador as a gift which, when a focused radio beam was aimed at it, would reflect and oscillate that beam due to vibrations in the air. https://en.wikipedia.org/wiki/The_Thing_%28listening_device%29 https://en.wikipedia.org/wiki/The_Thing_%28listening_device%...
- perch56 6y agoLeon Theremin was a genius that also created one of the first electronic instruments carrying his name now. https://en.wikipedia.org/wiki/Theremin https://en.wikipedia.org/wiki/Theremin
- russellbeattie 6y agoI remember in the 1990s I was doing contracting work in SoCal and got a job at one of the big defense contractors near LAX. (Trying to remember which one... Hughes?) I lasted only one week as the building was totally secure - no windows at all. Life is waaaaaay to short to work in a hole like that. Maybe someone with more info can fill in the details, but if I remember correctly, when Nokia changed their Silicon Valley offices to downtown Sunnyvale almost a decade ago, they were worried because Apple had offices in the adjacent building. If I remember correctly Nokia put in a bunch of security glass to prevent spying from vibrations in the windows. (There's some irony there, I know...)
- panda88888 6y agoYup. It's fairly standard. For classified work the rooms and entry/exit protocols have to meet certain security requirements based on the classification level. No windows and no electronics are standard. No walls that is exposed to the exterior. I've been in room within a room setup when it was warranted.
- acidburnNSA 6y agoBack in the 90's I found an old cardboard box full of radioshack electronics components and a paper schematic of how to put it together. I asked my dad what it was. He had been into an electronics hobby in the 1980s and told me that it was a amplifier to receiving laser light bounced off of a window for spy stuff. I couldn't believe it. The kit became my first significant soldering project. I got it all together and put my beloved laser pointer on a tripod and tried bouncing it in. I never did get it to the point that I could hear voices but boy could I ever hear cool vibration noises when I tapped the window. It was extremely fun and I've been soldering things here and there ever since.
- wallacrw 6y agoI've always wondered -- if I used this on the board room window to listen into public company earnings meetings, is that inside information? Technically, the information is "public" in that anyone could do what I'm doing...
- ColanR 6y agoI'm sure that one way or the other, that question has been dealt with exhaustively. My guess, the information you obtain is considered definitely not public, even though it's possible for a member of the public to obtain.
- pmoriarty 6y agoAlong similar lines, I've wondered about how often restaurant and bar owners have bugged their own premises. There's probably a lot of valuable information discussed in such establishments.. especially, say, around Wall St. Regarding the legal aspects, I'm not sure how much of a legal expectation of privacy one has in a "public" place such as a restaurant or bar, and we've pretty much already accepted ubiquitous video surveillance in such places (even if such videos are often without sound). Someone could potentially infer speech just by lipreading soundless videos, but if someone did decide to use audio surveillance on their own property in a bar, restaurant, or other place of business, is there any law against that? Quite apart from the legal and ethical objections that might arise against doing this, I'm sure some business owners are not above giving in to the temptation to spy on their patrons, especially if there's a big profit motive (like getting access to inside information by spying on Wall St execs gossiping over drinks or dinner). That's not to mention dirt that might be revealed in conversations considered to be "private", which could be used to blackmail people or for other nefarious purposes. The technology to perform such spying has been around for a long time, and in a bar or restaurant the owner (or rogue employee, or customer even) wouldn't have to resort to exotic techniques such as this light bulb trick. A simple microphone would suffice.
- briandear 6y ago> Along similar lines, I've wondered about how often restaurant and bar owners have bugged their own premises. In a few select Houston strip clubs.. all the time, or at least ten years ago some did, the ones owned by certain organizations. I haven’t been around that scene for a decade, so I can’t speak to now. I know of a few other places that seemed to magically never have trouble with city officials or permitting. Another such place, an after hours club, was frequented by the mayor’s “party-oriented” daughter, never had trouble with police raids, or fire marshals. The venue survived unscathed until the next mayor took over and such leverage became unavailable. The Texas Alcoholic Beverage Commission was the only real challenge, but often the local cops would be knowledgeable about pending raids and would graciously provide some advance notice. It certainly helped that many of those cops were paid as off duty private security by the venue. DEA was another frequent adversary, but those folks aren’t as undercover as they thought they were. I might suggest that the DEA was (or maybe still is,) one of the more sketchy law enforcement agencies in the government. Just under the surface of “normal,” there is some really fascinating stuff that goes on.
- imglorp 6y agoThe article involves a remote device watching the light bulb but it would also make sense to think about devices in the room as well. Your device might have its microphone disabled, in hardware even, but I wonder if the ambient light sensor has enough gain to see audio frequency variations in room lighting. We already know hard drives and speakers and whatever else can act like mics for exfiltration...
- deleted 6y ago[deleted]
- monadic2 6y agoPretty sure state intelligence has been doing this for decades, and we all know the laser-off-the-window pane trick by now. I’m much less worried about spies than I am about the powers directly around me, namely my own state and the large corporations that run society. I have no clue who greenlit this article but it seems starved for context not spoon-fed by the research team itself.
- irontinkerer 6y agoI was expecting to be dissapointed (I thought this was going to be a test in the same room, with perfectly calibrated equipment) but I was wrong. Very impressive that you can do this at that distance and with affordable ($400) equipment. I wonder how long intelligence agencies have been using this capability.
- hinkley 6y agoI knew someone who started building one of the laser based units in the fall of 1990, in high school. So that's 17 or 18? By the end of the decade or beginning of the next, we had telecom hardware companies filtering the signal to the activity LED so that you couldn't read packet info out of the flickering. Odds are good that someone combined those ideas a lot earlier than we might like to think.
- helios_invictus 6y agoI believe since the 80's
- helios_invictus 6y agoThis technology and technique has been known for a number of decades. Intelligence agency use a variety of counters to avoid this issue. SCIFs don't have windows for a reason. The standoff distance for intel buildings are far, and well monitored for similar reasons. Some facilties use double insulated glass with a randomized noise maker in the frame. Some corporate board rooms use similar technology and safe guards.
- feralimal 6y agoSorry - but that sounds like BS. Think about it - a hanging light bulb vibrates when you speak... Really? I don't see any movement, and I'm right there. But yet, that can be picked up 25m away by a telescope? With equipment that costs less than $1000? No way. Sounds like some phony story to me, that's meant to make us think spies have superpowers, or even that we're all being spied on. (Which we are, but not like this.)
- meritganset 6y agoI can't tell if this is serious or not. You realize that not all vibrations are visible by eye, right? In fact, the vast majority aren't.
- feralimal 6y agoDo you really think a telescope can pick up the reflected vibrations from a lightbulb, using a telescope 25m away?
- bbbobbb 6y agoHere similar experiment, 6 years ago: https://www.youtube.com/watch?v=FKXOucXB4a8 https://www.youtube.com/watch?v=FKXOucXB4a8 If you think that actual government agency cannot do even more easily with better equipment in 2020 you're kidding yourself.
- feralimal 6y agoI watched the video. I'm sorry, but its inane. This is the worst sort of science magic. In fact its just trickery. Do you seriously think that you have been provided evidence in that video? All that happened is that I ended up looking at a leaf and packets of things that weren't moving at all. That's not evidence! It says that they are picking up vibrations from a leaf or bag of crisps. But they don't show you those vibrations. They just give you a bunch of graphics and fuzzy sounds and tell you that they have done something. You do see that this is could be very simple video trickery right? As with the initial article - there's a claim, but nothing to really be able to use to verify that claim. Just a graphic, and references to Shazam. Perhaps this is guerrilla marketing for Shazam? Its a more viable thesis anyway, given the evidence!
- GhostVII 6y agoImportant caveat: The voice and music recordings they used in their demonstrations were also louder than the average human conversation, with speakers turned to their maximum volume I can clearly see vibrations in glass near loud speakers with my naked eye, but when someone is speaking I generally can't see any vibrations. Still really cool that they were able to reproduce sounds this way, but it's not like you can spend 1k and be able to actually listen to conversations using this method.
- lostmyoldone 6y agoIf their chart is correct, the 30cm mirror show a 20db improvement in SNR at 200Hz compared to 20cm, same curve but 20db lower gain. That is an absolute crazy scaling, I'm not entirely sure how that's possible, though I have a suspicion. If it's an actual scaling law that can be exploited, I would expect you can extend this to entirely practical audio volumes on a shoestring budget.
- codezero 6y agoIn college for a project I wanted to encode messages over small brightness variations in light bulbs. It's a pain to deal with AC, so I ended up doing it with a laser pointer. It turned out to be stupidly easy with a laser pointer and photodiode attached almost directly to a pair of PC speakers. All these devices have a +5v DC signal. I could attach my iPod headphones to the laser pointer directly, then the photodiode to the speakers, and boom, music at about 100 yards, with almost no quality decrease, though I didn't do anything quantitative :) I've always wondered what places communication started getting hidden since we went online and no longer rely on things like numbers stations or drop boxes (though I assume dead drops still exist)
- amatecha 6y agoK what? That's amazing! Apparently I need to learn more about lasers.... haha :) I guess it's pretty "fragile" since the slightest misalignment of the source laser & destination sensor would mean a total loss of signal, right?
- dwohnitmok 6y agoGiven that the laser forms a spot, minor misalignments are very easy to debug (just line up the red spot with the sensor again). Also given a laser with sufficiently wide spread, minor misalignments would manifest themselves as volume loss. Not great if you don't have easy access, but reliable enough for e.g. a dorm room or a living room. This was a lab we did in an intro EE class in college and it worked wonders as a "whoa cool" demonstration with very basic EE knowledge required.
- wonderlg 6y agoYou’ll probably also need to debug it often on warm summer evenings.
- rorykoehler 6y agoYou should find out how the starlink network will communicate if you're worried about accuracy.
- pier25 6y agoThis is only for incandescent lightbulbs, right?
- kainer 6y agoThose stories keep fascinating me, ever since I talked about side-channel attacks during my study times. Re-creating CRT images through walls, listening in on keystrokes through the electric wires of a building or learning about traffic patterns while observing network interface flashing LEDs. Just a fascinating world when you leave aside what they are aimed towards.
- Jestar342 6y agoA friend of mine had a side-gig at an electronics factory that used to fit/repair government printers, telegram, and fax machines in the 80s. When he first started he noted that the schematics said to double up the number of capacitors. When he raised this as a potential error in the schematic with his boss, he was told that it was quite deliberate and was there to stop giving away what was being printed by anyone measuring the power fluctuations. Feels kinda obvious now but when I first heard it I had a mini-mind-blown moment.
- polishdude20 6y agoThat seems like a good way to make a piece of equipment just not work. The stuff inside the printers also probably relies on proper capacitor values.
- jstanley 6y agoSeems unlikely. It's probably ~all digital, so I expect the capacitors are literally only there for filtering the power supply.
- deleted 6y ago[deleted]
- gugagore 6y agoIf you learn about https://en.m.wikipedia.org/wiki/Decoupling_capacitor https://en.m.wikipedia.org/wiki/Decoupling_capacitor you'll see that there is more to the consideration than "just use the highest capacitance capacitor".
- IAmGraydon 6y agoPower caps. They act like a shock absorber or a very short term UPS for incoming power.
- gugagore 6y agoA shock absorber contains an element that does damping and a spring. The ideal capacitor can only be one of those elements in the analogy, I think.
- Puts 6y agoApparently this is 1947-tech: https://en.wikipedia.org/wiki/Laser_microphone https://en.wikipedia.org/wiki/Laser_microphone I even remember there where schematics for a laser-microphone circulating on the early 2000s internet that could translate the vibrations of windows into sound.
- OkayPhysicist 6y agoI built one of those in college. Hardware's super simple, but actually getting it alligned is a total PITA.
- Romanulus 6y agoAll cool tech aside, I'll be sure to update the single light-bulb hanging from a thread in my interrogation room now.
- draw_down 6y agoTo defeat this, don't you just do what the mobsters in movies do? Play music or make some other loud noise and then whisper or talk softly close to each other?
- mdturnerphys 6y agoPrevious discussion of source: https://news.ycombinator.com/item?id=23498185 https://news.ycombinator.com/item?id=23498185
- 2OEH8eoCRo0 6y agoDidn't anyone watch or read Clear and Present Danger? Laser microphone. This has been done for the past 40 years or so.
- Dahoon 6y agoOf course it is Israeli..
- fortran77 6y ago@dang -- this seems like an unproductive comment.
- Stratoscope 6y agoThe best thing to do when you see a comment like that is to click on the "n hours/minutes ago" link next to the username to open the comment on its own page. There you will find a "flag" link as well the downvote button (they do separate things). If enough users flag a comment it will turn "[flagged] [dead]" automatically.
- partiallypro 6y agoI'm not sure on the cost, but I know it's common to use lasers at an angle on windows to spy on conversations via a laser microphone. That requires less of a line of sight. Is this a cheaper method?
- deleted 6y ago[deleted]
- opal9 6y agothis sounds like something samy kamkar would make
- mycall 6y agoStealth light bulbs. Create all angles that won't reflect light back to source.
- deleted 6y ago[deleted]
- arkanciscan 6y agoI suspect this only works on incandescent bulbs. My house is full of Philips Hue bulbs, so suck it spies!!!
- anigbrowl 6y agoI'm getting tired of these stories, it's always the same set of researchers doing different variations on the same thing, and feels increasingly like pg's submarine.
- badrabbit 6y agoWell color me surprised /s
- josefrichter 6y ago“Published spying technique” – ironic
- Milank 6y agoOne more reason to use LED!