PriHorus: Privacy-Preserving RSS-Based Indoor Positioning

Indoor positioning service (IPS) allows users to navigate in large and unfamiliar indoor venues with no or unreliable GPS signals. Received Signal Strength (RSS)-based IPS has received much attentions during the past decade because it does not require costly infrastructure update but makes use of WiFi infrastructure readily available and ubiquitous smartphones. While IPS can greatly facilitate human indoor activities, it also raises serious privacy concerns as periodical location queries submitted by users allow the IPS server to continuously track users' whereabout. In addition, a curious user may infer the fingerprint database stored at the IPS server. This paper introduces PriHorus, a privacy-preserving indoor positioning scheme built upon Horus, a representative RSS-based indoor positioning system. PriHorus can protect both users' location privacy and IPS server's data privacy while achieving the same level of location accuracy as in the original Horus system.