A team from Germany’s Karlsruhe Institute of Technology has demonstrated that modern Wi-Fi routers emit unencrypted feedback signals which can be intercepted to identify people by their walking patterns, even without access to passwords or devices.
- Wi-Fi 5+ routers emit unencrypted signals that reveal user movement
- Researchers identified individuals with 99.5% accuracy via signal patterns
- No need for Wi-Fi password or device possession to be tracked
What happened
Researchers at Karlsruhe Institute of Technology discovered a privacy vulnerability in Wi-Fi routers that support Beamforming Feedback Information (BFI). These routers send feedback signals to connected devices to optimize performance, but the signals themselves are transmitted unencrypted and can be intercepted by nearby devices.
By analyzing how a person’s movement, particularly their walking gait, disrupts these radio waves, the researchers were able to identify volunteers with nearly perfect accuracy. This tracking method does not require access to the router’s password or physical connection, relying instead on signal analysis alone.
Why it matters
The findings reveal that everyday routers, even in public spaces like cafes or offices, could be covertly used to surveil and identify people without their knowledge or consent. Such tracking is possible even if the target is not carrying any Wi-Fi enabled devices, making it a potent new privacy threat.
This risk raises significant concerns for consumer privacy and security standards in wireless technology. The research team calls for enhancements in Wi-Fi protocol design to encrypt or otherwise protect BFI signals to prevent unauthorized surveillance.
What to watch next
Industry response will be crucial as standards organizations consider how to secure or redesign beamforming feedback data in future Wi-Fi versions. Monitoring advancements in Wi-Fi 6E and Wi-Fi 7 standards may highlight if these vulnerabilities are addressed.
Users and businesses should be aware of the potential for Wi-Fi-based surveillance and advocate for privacy protections. Meanwhile, the research underscores the need for continuous scrutiny of emerging wireless technologies to safeguard personal privacy.