A recent study conducted by A scientific team composed of the Israeli Ben Gurion University of the Negev and the Weizmann Institute of Science in Israel suggests that hackers can now listen to your conversations from 25 meters away using a light bulb which is in your room using Telescopes, optical sensor.
Lamphone Technique for Spying
Unlike similar attacks that analyze the impact of sound waves on nearby objects, this version is passive and external, and the most critical thing is that it can be carried out in real time. To prove the effectiveness of the attack, the team’s target location was an office on the third floor of an office building. The curtain wall can reduce the light from the office and cover the whole building. The target office contains a hanging E27 LED bulb (12 watts).
Hackers can Listen through your Light Bulb
The eavesdropper is located on a pedestrian bridge, located at an air distance of 25 meters from the target office. The researchers used three telescopes with different lens diameters of 10,20 & 35 cms in this experiment.
The team installed a photoelectric sensor (Thorlabs PDA100A2, which is an amplified switchable gain light sensor consisting of photodiodes used to convert light to voltage) on a telescope at a time. The voltage is obtained from the photoelectric sensor through the 16-bit ADC NI-9223 card, and processed in the LabVIEW script we have written. The sound played in the office during the experiment was not heard at the location of the eavesdropper.
Lamphone-Data transfer and decoding process:
Using this technology can capture and convert to audio with high quality, and can even be recognized by the music recognition application Shazam. At the same time, this speech was successfully transcribed by Google’s text-to-speech API. Ben Nassi, Boris Zadov, and Yaron Pirutin, security researchers at Ben-Gurion University, jointly developed the technology. He said they hope to raise awareness of this attack vector and let both parties know what is possible.