Researchers claim discovery of remote eavesdropping method using light bulbs

Black HatResearchers at a university in Israel claim to have discovered a new low-tech eavesdropping technique, which relies on sound vibrations on the glass surface of light bulbs and requires equipment costing less than $1,000. The researchers claim that the technique, which they call “lamphone”, enables eavesdroppers to intercept, in real time, audible conversations from a room located hundreds of feet away, simply by recording the vibrations that sounds create on the glass surface of a common light bulb present in the room.

The announcement was made by Ben Nassi, Yaron Pirutin and Boris Zadov, who work at the Ben-Gurion University of the Negev and the Weizmann Institute of Science, near Tel Aviv. The three researchers said they used a low-cost telescope, which they placed nearly 100 feet from a target room containing a commercially available standard light bulb. They then placed each telescope behind a $400 electro-optical sensor. The goal of the contraption was to measure the minuscule changes in light output from the bulb, which are caused by sound vibrations off the bulb’s surface.

The electrical signals captured by the telescopes were digitized using commercially available analog-to-digital converters, before being transferred onto a laptop. The researchers then used commercially available software to filter out noise, and were gradually able to reconstruct clearly audible recordings of the sounds inside the target room. They claim that the resulting recording is clearly audible and can even be transcribed using Google speech-to-text software.

The three Israeli researchers say they now plan to present their findings at the Black Hat security conference in August, which will be held virtually due to health concerns caused by the coronavirus pandemic. Speaking to Wired magazine last weekend, they said that their goal is “not to enable spies or law enforcement, but to make clear to those on both sides of surveillance what’s possible”. “We’re not in the game of providing tools”, they said.

Author: Joseph Fitsanakis | Date: 15 June 2020 | Permalink

One Response to Researchers claim discovery of remote eavesdropping method using light bulbs

  1. Peter Wallerberger says:

    certainly an advance over the hardwired version planted in a ceiling downlight over the conference table !! (abit of a giveaway as such a apparatus was easily identified as being the only light out in the room). I note that one building I worked in had devices on each window pane to simulate vibration in the glass in order to destroy any chance of an external laser ‘reading’ the reasonance and converting it back into audible speech.(but – that was twenty five years ago!!)I wonder how that would affect the light senseing recorder used by the Israelies??
    Of course – many government agencies have windows blocked off with copper covers – if theyre really smart they won’t have windows at all and the room in question will be completely lined with copper.
    I take my hat off too the researchers – they have done very , very well but they shouldn’t give up their night jobs just yet as there is much more to discover but they certainly are headed in the right direction….Perhaps unsurpriseing, as I.D.F has produced some incredable technology over the last twenty or so years – afterall, their very survival as a nation is dependant upon it.

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