Interference-Negligible Privacy-Preserved Shield for RF sensing

Abstract

Researchers have demonstrated the feasibility of detecting human motion behind the wall with radio frequency (RF) sensing techniques. With these techniques, an eavesdropper can monitor people's behavior from outside of the room without the need to access the room. This introduces a severe privacy-leakage issue. To address this issue, we propose Aegis, an interference-negligible RF sensing shield that i) incapacitates the RF sensing of eavesdroppers that work on any WiFi frequency bands and at any unknown locations outside of the protected area; ii) has minimum interference to the on-going WiFi communication; and iii) preserves authorized RF sensing inside the private region. Our extensive evaluation shows that when Aegis is activated, the accuracy of legitimate sensing system only decreases by 0.08, while the accuracy of the illegitimate sensing system is as low as 0.04. Moreover, the on-going data communication throughput is even increased by 10MB/s on 2.4GHz WiFi band and 5MB/s on 5GHz WiFi band.