Securing peer-assisted indoor localization leveraging acoustic ranging

•We carefully survey the attacks to the peer-assisted indoor localization.•We propose the defenses to deal with attacks launched by the dishonest peers.•We propose the defense against the intentional interference of outside attackers.•We give the detailed theoretical proofs about our proposed countermeasures. Peer-assisted indoor localization leverages the pairwise acoustic ranging among the nearby peer phones to refine the location estimation of WiFi-based indoor localization. This technique significantly pushes the localization accuracy, but when it is applied, it will suffer from various attacks from both inside (i.e., the dishonest peers involved) and outside. The dishonest peers may violate the server’s schedule to emit their ranging signals or manipulate their recorded audio data, both of which can impact the distance measurements. The outside attackers may continually broadcast the interference signals to influence the signal detection in the acoustic ranging. All these attacks can have a great impact on the final location estimation. In this paper, we propose the defenses against these attacks. We first propose an algorithm to identify the honest peers in current localization by searching for devices that can be embedded into the same plane according to distance measurements among them. To defend against the intentional interference of outside attackers, we design a robust acoustic ranging method that exploits signal modulation. Experimental results demonstrate that our countermeasures can greatly improve the robustness of peer-assisted localization.