Spies can listen to your conversations by watching a light-bulb in the Room

Lamphone Attack could let spies listen to your conversations remotely just by watching a light bulb in the room.

   

       I think you might not believe this but it's possible to spy on secret conversations happening in a room from by a nearby location just by observing the light bulb.

Recently, a team of cybersecurity researchers demonstrated a novel side-channel attacking technique that can be applied by eavesdroppers to recover full sound from the victim's room.

A scientific team from "Ben Gurion University" in israel demonstrated a magical eavesdropping technique that can be done with just one laptop, a bulb, and equipment worth less than $1,000. The technique is known as "Lamphone" side channel attack uses photoelectric sensors to analyse frequency response of bulb to the sound. The "lamphone" measures the tiny light fluctuations that sound waves produce when they hit the bulb and causes it to vibrate slightly. The electro optical-sensor isolates the audio signal from the optical signal in four stages.

    To prove the effectiveness of the attack the team targeted an office on the third floor of an office building. Curtain walls reduce the amount of light emitted by the office and cover the entire building. The target office contains a suspended E27 LED bulb which is of 12 watts.

The eavesdropper was located on a footbridge, located 25m above the target's office. The experiment described in this section was carried out using three different lens diameters (10, 20, 35 cms) of telescopes.

  The team installed a photoelectric sensor on one telescope at a time, a large switchable gain light sensor consisting of photodiodes used to convert light into voltage. The voltage is obtained from the photoelectric sensor. The sound played in the office during the experiment is not heard in the location of eavesdropper.

This technology enables high quality capture and conversion into audio, even being recognised by the most popular music recognition app "Shazam". At the same time the voice was successfully transcribed by the Google's text-to-speech API. 

Privacy is a Myth!!