Security News > 2020 > June > New Eavesdropping Technique Relies on Light Bulb Vibrations
A group of security researchers has devised a new technique for eavesdropping on conversations that relies on the analysis of a light bulb's frequency response to sound.
Called Lamphone, the novel side-channel attack demonstrates that fluctuations in the air pressure on the surface of the hanging bulb can be exploited to recover speech and singing in real time, using a remote electro-optical sensor placed externally.
Researchers from the Ben-Gurion University of the Negev and Weizmann Institute of Science came up with an algorithm to recover sound from the optical measurements of the vibrations of a light bulb.
In a real-world test scenario, Lamphone successfully recovered both human speech and singing from a bridge 25 meters away from the target room where the light bulb was hanging.
A hanging E27 LED bulb was in the room and curtain walls would cover the entire building, thus reducing the amount of light emitted from the offices.