Karlston Posted June 14, 2020 Share Posted June 14, 2020 Spies Can Eavesdrop by Watching a Light Bulb's Vibrations The so-called lamphone technique allows for real-time listening in on a room that's hundreds of feet away. Photograph: Michael Blann/Getty Images The list of sophisticated eavesdropping techniques has grown steadily over years: wiretaps, hacked phones, bugs in the wall—even bouncing lasers off of a building's glass to pick up conversations inside. Now add another tool for audio spies: Any light bulb in a room that might be visible from a window. Researchers from Israeli's Ben-Gurion University of the Negev and the Weizmann Institute of Science today revealed a new technique for long-distance eavesdropping they call "lamphone." They say it allows anyone with a laptop and less than a thousand dollars of equipment—just a telescope and a $400 electro-optical sensor—to listen in on any sounds in a room that's hundreds of feet away in real-time, simply by observing the minuscule vibrations those sounds create on the glass surface of a light bulb inside. By measuring the tiny changes in light output from the bulb that those vibrations cause, the researchers show that a spy can pick up sound clearly enough to discern the contents of conversations or even recognize a piece of music. "Any sound in the room can be recovered from the room with no requirement to hack anything and no device in the room," says Ben Nassi, a security researcher at Ben-Gurion who developed the technique with fellow researchers Yaron Pirutin and Boris Zadov, and who plans to present their findings at the Black Hat security conference in August. "You just need line of sight to a hanging bulb, and this is it." In their experiments, the researchers placed a series of telescopes around 80 feet away from a target office's light bulb, and put each telescope's eyepiece in front of a Thorlabs PDA100A2 electro-optical sensor. They then used an analog-to-digital converter to convert the electrical signals from that sensor to digital information. While they played music and speech recordings in the faraway room, they fed the information picked up by their set-up to a laptop, which analyzed the readings. The researchers' experimental setup, with an electro-optical sensor behind the eyepiece of a telescope, pointing at a lightbulb inside an office building more than 80 feet away.Courtesy of Ben Nassi The researchers found that the tiny vibrations of the light bulb in response to sound—movements that they measured at as little as a few hundred microns—registered as a measurable changes in the light their sensor picked up through each telescope. After processing the signal through software to filter out noise, they were able to reconstruct recordings of the sounds inside the room with remarkable fidelity: They showed, for instance, that they could reproduce an audible snippet of a speech from President Donald Trump well enough for it to be transcribed by Google's Cloud Speech API. They also generated a recording of the Beatles' "Let It Be" clear enough that the name-that-tune app Shazam could instantly recognize it. The technique nonetheless has some limitations. In their tests, the researchers used a hanging bulb, and it's not clear if a bulb mounted in a fixed lamp or a ceiling fixture would vibrate enough to derive the same sort of audio signal. 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. But the team points out that they also used a relatively cheap electro-optical sensor and analog-to-digital converter, and could have upgraded to a more expensive one to pick up quieter conversations. LED bulbs also offer a signal-to-noise ratio that's about 6.3 times that of an incandescent bulb and 70 times a fluorescent one. Regardless of those caveats, Stanford computer scientist and cryptographer Dan Boneh argues that the researchers' technique still represents a significant and potentially practical new form of what he calls a "side channel" attack—one that takes advantage of unintended leakage of information to steal secrets. "It's a beautiful application of side channels," Boneh says. "Even if this requires a hanging bulb and high decibels, it’s still super interesting. And it’s still just the first time this has been shown to be possible. Attacks only get better, and future research will only improve this over time." But Nassi points out that the video-based technique, while far more versatile since it doesn't require a bulb to be visible in the room, requires analysis of the video with software after it's recorded to convert the subtle vibrations observed in an object into the sounds it picked up. Lamphone, by contrast, enables real-time spying. Since the vibrating object is itself a light source, the electro-optical sensor can pick up vibrations in far simpler visual data. That could make lamphone significantly more practical for use in espionage than previous techniques, Nassi argues. "When you actually use it in real time you can respond in real time rather than losing the opportunity," he says. Still, Nassi says the researchers are publishing their findings not to enable spies or law enforcement, but to make clear to those on both sides of surveillance what's possible. "We want to raise the awareness of this kind of attack vector," he says. "We’re not in the game of providing tools." As unlikely as being targeted by this technique is, it's also easy to forestall. Just cover any hanging bulbs, or better yet, close the curtains. And if you're paranoid enough to be concerned about this sort of spy game, hopefully you've already used anti-vibration devices on those windows to prevent eavesdropping with a laser microphone. And swept your house for bugs. And removed the microphones from your phone and computer. After all, in an era when even the light bulbs have ears, a paranoiac's work is never done. Spies Can Eavesdrop by Watching a Light Bulb's Vibrations Link to comment Share on other sites More sharing options...
funkyy Posted June 15, 2020 Share Posted June 15, 2020 OMG!! Months ago on another thread on Nsane about government eavesdropping through Smart TV's I said "Next they'll be spying on us through our lightbulbs". I'm just going to send my application form to the FBI, CIA, MI5 and Mossad. Link to comment Share on other sites More sharing options...
Marcus Thunder Posted June 15, 2020 Share Posted June 15, 2020 10 hours ago, funkyy said: OMG!! Months ago on another thread on Nsane about government eavesdropping through Smart TV's I said "Next they'll be spying on us through our lightbulbs". OMG, OMG, OMG... I remember that I read that comment & I thought to myself how lame & unrealistic that comment was! 10 hours ago, funkyy said: I'm just going to send my application form to the FBI, CIA, MI5 and Mossad. You totaly got the brains for it Link to comment Share on other sites More sharing options...
TrojanK Posted June 15, 2020 Share Posted June 15, 2020 10 hours ago, funkyy said: OMG!! Months ago on another thread on Nsane about government eavesdropping through Smart TV's I said "Next they'll be spying on us through our lightbulbs". I'm just going to send my application form to the FBI, CIA, MI5 and Mossad. True 👇 Link to comment Share on other sites More sharing options...
Marcus Thunder Posted June 16, 2020 Share Posted June 16, 2020 On 6/14/2020 at 9:36 PM, Karlston said: And if you're paranoid enough to be concerned about this sort of spy game, hopefully you've already used anti-vibration devices on those windows to prevent eavesdropping with a laser microphone. And swept your house for bugs. And removed the microphones from your phone and computer. Paranoid conspiracy theorists always keep the TV on to make it harder to spy on real conversations, they missed that one. Link to comment Share on other sites More sharing options...
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