Engineers have created a gadget that recognizes wiretapping through laptop microphones

Employees of the National University of Singapore and Yonsei University in South Korea submittedTickTock: Detecting Microphone Status in Laptops Leveraging Electromagnetic Leakage of Clock Signals / arXiv development that will help detect wiretapping through a laptop microphone.

Called TickTock, the technology is based on a Raspberry Pi 4 board, a near-field probe, an RF amplifier, and a digital SDR transceiver. The principle of operation relies on the fact that digital MEMS microphones on conventional laptops emit electromagnetic signals when they are active. TickTock catches them and notifies the user that they can listen.

TickTock technology needs to be adapted to each laptop model as manufacturers use different sound chips in their devices. Also difficult is the noise filtering of other components of the laptop.

After setting up the hardware, the engineers were able to successfully test TickTock with computers from manufacturers such as Lenovo, Fujitsu, Toshiba, Samsung, HP, Asus, and Dell. It is noteworthy that the technology was unable to determine when the microphones are turned on on Apple devices: MacBooks of 2014, 2017 and 2019 model years participated in the test.

The researchers also tested their development on smartphones, smart speakers, tablets and external webcams, but the test results were not particularly successful: out of 40 tested devices, TickTock coped with only 21. Engineers attribute the low level of efficiency to the use of analog microphones and short conductors in these gadgets, which emit a weaker signal compared to laptops.

In the future, the final form of the TickTock device will look like a USB stick that can be placed next to or attached to a laptop.