Spies can eavesdrop remotely by analyzing a light bulb's vibrations

Shawn Knight

Posts: 13,080   +131
Staff member

The “lamphone” measures the tiny fluctuations in light created as sound waves hit the bulb and cause it to vibrate ever so slightly. The electro-optical sensor is able to isolate the audio signal from the optical signal through four stages.

Unlike similar attacks that analyze the effects of sound waves on nearby objects, this version works passively, externally and most critically, in real time.

To demonstrate the effectiveness of the attack, the team set up a test using an office building with a hanging e27 light bulb and positioned a telescope 25 meters away on a walkway. Two songs and an excerpt of a speech from Donald Trump were then played in the room, none of which could be heard from the outside location.

Impressively, the technique was able to capture and convert the audio at a high enough quality to be recognized by music identifying app Shazam. The speech, meanwhile, was successfully transcribed by Google’s text-to-speech API.

Ben Nassi, the security researcher at Ben-Gurion University who developed the technique with fellow researchers Boris Zadov and Yaron Pirutin, said they want to raise awareness for this kind of attack vector so both sides of surveillance know what is possible.

As Wired notes, the technique does have its limitations. The use of a hanging light bulb rather than a bulb in a fixed socket suggests that the latter (and more common) solution might not afford enough vibration to be effective. It was also noted that the voice and music recordings were played at volumes that were “louder than the average human conversation.”

Furthermore, the test was conducted at a range of 25 meters although the distance could be increased with proper equipment, like a bigger telescope or a more capable electro-optical sensor.

Permalink to story.

 

Uncle Al

Posts: 8,001   +6,775
So, you send your X an anonymous gift of these bulbs then eavesdrop on her to make sure the kids are happy? I wonder how law enforcement can use this to get around current laws concerning bugging devices? It certainly demands a look by the courts to be sure information isn't being gained illegally or used illegally against people .....
 

QuantumPhysics

Posts: 4,739   +5,160
I think we've all known about laser mics where you can point a laser at a window and the laser can translate the vibrations of the window into sound.

HAL used it in 2001 Space Odyssey.

It's a lot easier to just use Wifi to hack someone's home speaker or smartphone or desktop camera.
 

psycros

Posts: 3,407   +3,910
I think we've all known about laser mics where you can point a laser at a window and the laser can translate the vibrations of the window into sound.

HAL used it in 2001 Space Odyssey.

It's a lot easier to just use Wifi to hack someone's home speaker or smartphone or desktop camera.

Was literally going to post that. This has been a known phenomenon since the late 80's. This spycraft led to the creation of the CD. But you're wrong about HAL: he was actually lip reading. Also, WiFi hacking isn't nearly as easy as its made out to be and is getting more difficult all the time. Most of the smart device hacking is done either at the router or via factory-installed malware.
 

Vulcanproject

Posts: 1,333   +2,321
Complete passivity is golden. Loved the story of the Soviet great seal bug, but you still had to energise it with an illuminating radio beam.

I always try to see the thickness and design of the windows in the oval office when I see good footage. Supposedly fitted with anti spy devices that vibrate the panes randomly, as well as being blast proof and so forth. It's hidden well. Hard to know what else exactly is in there. Plenty of talk about how there are sensors everywhere, and secret signals built into various facets of the room to alert the Secret Service. Possibly BS, but also sounds pretty sensible too.

Perhaps in other sensitive areas you'll also have to watch light bulb frequency now!
 

Bullwinkle M

Posts: 454   +350
Are they using an E27 LED with a glass bulb?

Many types of plastic bulb are easier to damp

No matter, just use a wi-fi or bluetooth "plastic" bulb LED with built in speaker and play white noise when required....

Or close the curtains!
 
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PEnnn

Posts: 612   +584
What kind of bulb?? Incandescent? LED? Fluorescent? Bug Zapper?? The article doesn't enlighten us.....pardon the pun.

What if there are 5 people talking at the same time? What if it was a sunny day?? And I assume it has to be a bare bulb hanging from the ceiling? Recessed lighting is a problem, right??

Sometimes I think Ben Gurion University / Weizman Inst. pay TS a stipend to publish such ludicrous articles about those amazing achievements.
 

Bullwinkle M

Posts: 454   +350
What kind of bulb?? Incandescent? LED? Fluorescent? Bug Zapper?? The article doesn't enlighten us.....pardon the pun.

What if there are 5 people talking at the same time? What if it was a sunny day?? And I assume it has to be a bare bulb hanging from the ceiling? Recessed lighting is a problem, right??

Sometimes I think Ben Gurion University / Weizman Inst. pay TS a stipend to publish such ludicrous articles about those amazing achievements.
a hanging E27 LED bulb (12 watt).

Link to research is in the article
 

hk2000

Posts: 153   +81
That's just ridiculous! How are they accounting for vibrations caused by HVAC systems, among a myriad of other atmospheric pressure factors?! This is a proof of concept experiment that really isn't, if the people in the room are cooperating with the conductors of the experiment.
This is akin to a "hide and seek" game where the person who's hiding actually wants to be found!
 

hk2000

Posts: 153   +81
I think we've all known about laser mics where you can point a laser at a window and the laser can translate the vibrations of the window into sound.
Yep- makes a lot more sense than this. Back in the 90's, I recorded a lot of phone conversations using a similar technique- (MIC built into a suction cup connected to a tape recorder.)
 

mbk34

Posts: 153   +90
I always try to see the thickness and design of the windows in the oval office when I see good footage.
There's no need to use expensive monitoring equipment to monitor the oval office. You can simulate most of the important presidential decisions fairly accurately with just a lucky 8 ball.
 

Adhmuz

Posts: 2,119   +924
This is interesting, but if CSI has taught me anything of value its that you can take a video surveillance system's audio-less recordings and analyses the vibration in plants caused by people talking within close proximity and extract perfect quality recordings to then incriminate those individuals.
 

mbrowne5061

Posts: 1,808   +1,040
I think we've all known about laser mics where you can point a laser at a window and the laser can translate the vibrations of the window into sound.

HAL used it in 2001 Space Odyssey.

It's a lot easier to just use Wifi to hack someone's home speaker or smartphone or desktop camera.

Except this could potentially be made to work without a windows. Imagine an outdoor space, no windows, lit by string lights but with too much background noise along the line of sight for a parabolic microphone. Pointing a telescope at the lights could potentially allow for the capture of sensitive information (I see no reason why the technique's sensitivity couldn't be refined). You could probably even localize your data collection even further by targeting the bulb closest to the audio source you're interested in.

Obviously, this is a highly specialized technique, but so is the 'aim a laser as the window' method.