Security researchers from the Ben-Gurion University and the Weizmann Institute of Science have revealed a vector of cyber attack as innovative as it is unexpected, the process of which involves the light of a light bulb.
This is a study that could well encourage us to work in the dark. A latest research revealed by researchers from Ben-Gurion University and the Weizmann Institute of Science, unveils a vector of cyber attack that goes through … a light bulb. Several months ago, several Israeli researchers had already revealed a hack technique for intercepting data using variations in the brightness of LCD screens.
Called Lamphone, this last method for stealing data proves to be as innovative as it is unexpected: “this attack is carried out using a remote electro-optical sensor to analyze the frequency response of a light bulb suspended from sound”, explained researchers including Yuval Elovici who had previously worked on the Brignthness hack technique. “We show how the fluctuations of air pressure on the surface of the hanging bulb (in response to sound), vibrating very slightly (a millidegree vibration), can be exploited by listening to recover speech and song , passively, externally and in real time ”.
1 alarm, 1 song and 1 speech reconstituted
“We analyze the response of a light bulb suspended to sound via an electro-optical sensor and learn how to isolate the audio signal from the optical signal. Based on our analysis, we develop an algorithm to recover sound from optical measurements obtained from the vibrations of a bulb and picked up by the electro-optical sensor. We evaluate the performance of Lamphone in a realistic configuration and show that Lamphone can be used by wiretaps to recover human speech (which can be identified precisely by the Google Cloud Speech API) and singing (which can be identified with precision by Shazam and SoundHound) from a bridge 25 meters from the target room containing the hanging light bulb, ”continue the researchers.
To make this hack, the researchers used a simple 12-watt E27 LED bulb. For this experiment, three telescopes were used, including with lenses of three different diameters (10, 20 and 35cm) on which electro-optical sensors (Thorlabs PDA100A2) connected to 16-bit processing cards (ADC NI-9223) have been mounted. The latter pointed below at a distance of 25m from an office located in a building. “The SNR [rapport signal sur bruit ] from optical measurements from each telescope and acoustic measurements were obtained from microphones. Based on these results, we created an equalizer, ”say the researchers. Among the sounds reconstructed using this technique: an audible alarm, the song Let it be and the famous presidential phrase “we will make America great again” by Donald Trump.