Paper accepted at USENIX Security 2025: “Sound of Interference”
Digital MEMS microphones, widely used in laptops and smart speakers, transmit captured sound as a pulse density modulation (PDM) digital signal. This work shows that the electromagnetic emanations from that PDM signal can be received from a distance and used to reconstruct the audio the microphone is picking up.
The work is a collaboration between the Sugawara group at The University of Electro-Communications and the University of Florida. Beyond characterizing the eavesdropping mechanism, the paper examines countermeasures available on the device design side.
[Paper]
Arifu Onishi, Sri Hrushikesh Varma Bhupathiraju, Rishikesh Bhatt, Sara Rampazzi, Takeshi Sugawara, “Sound of Interference: Electromagnetic Eavesdropping Attack on Digital Microphones Using Pulse Density Modulation,” 34th USENIX Security Symposium (USENIX Security 2025), pp. 3865-3884, Seattle, WA, USA, August 2025.