Users are Closer than they Appear: Protecting User Location from WiFi APs

Abstract

Wi-Fi-based indoor localization has now matured for over a decade. Most of the current localization algorithms rely on the Wi-Fi access points (APs) in the enterprise network to localize the Wi-Fi user accurately. Thus, the Wi-Fi user's location information could be easily snooped by an attacker listening through a compromised Wi-Fi AP. With indoor localization and navigation being the next step towards automation, it is important to give users the capability to defend against such attacks. In this paper, we present MIRAGE, a system that can utilize the downlink physical layer information to create a defense against an attacker snooping on a Wi-Fi user's location information. MIRAGE achieves this by utilizing the beamforming capability of the transmitter that is already part of the Wi-Fi standard protocols. With this initial idea, we have demonstrated that the user can obfuscate his/her location from the Wi-Fi AP always with no compromise to the throughput of the existing Wi-Fi communication system through the real-world prototype, and reduce the user location accuracy of the attacker from 2.3m to more than 10m through simulation.