POSTER: LocMask: A Location Privacy Protection Framework in Android System

The mobile users are facing a serious risk of losing location privacy (e.g., users' location information transmitted by open advertisement network, and the reported event of involuntary tracking of mobile users in popular mobile social apps). In this study, we design and implement LocMask, a system-level solution that provides location privacy protection in Android system. LocMask achieves the tradeoff of the privacy and the utility of location based services by providing the Quality of Protection (QoP) on demand, which sets different privacy protection levels to different locations based on how sensitive these locations are. Motivated by the fact that Top locations (e.g, user's home or office) are more sensitive than less visiting locations, LocMask provides location profile management module that records the user's mobility history and ranks the locations in terms of the user's visiting frequency. With users' location profiles, LocMask can automatically determines the sensitiveness of these locations as well as their corresponding privacy protection level. LocMask is also designed to incorporate various obfuscation techniques. The effectiveness of LocMask is supported by extensive real-world data based evaluations.