Researchers identify people through ordinary Wi-Fi routers with 99.5% accuracy

Karlsruhe Institute of Technology researchers showed that standard Wi‑Fi routers can identify nearby people with up to 99.5% accuracy.

Their BFId method uses unencrypted beamforming feedback from ordinary Wi‑Fi devices, with no special hardware or target device needed.

The system was tested on 197 participants and presented at ACM CCS, highlighting a new passive surveillance risk.

The work raises privacy concerns and suggests upcoming Wi‑Fi sensing standards like IEEE 802.11bf need stronger safeguards.