German researchers have developed a system that identifies people with nearly 100% accuracy using traditional Wi-Fi signals.
Scientists from Karlsruhe Institute of Technology analyze reflected radio waves to create a visual model of the environment and people.
No active device is needed; even a switched-off phone does not guarantee protection.
Professor Thorsten Strufe explains: "Monitoring radio wave propagation allows us to create a visual model, like a camera using radio waves instead of light."
The system uses standard communication protocols between routers and devices. Beamforming data is transmitted unencrypted, making it accessible to anyone in range.
The researchers call for stronger privacy and security guarantees in the upcoming Wi-Fi IEEE 802.11bf standard.
Results will be presented at the ACM CCS conference in Taipei.
