JointCache: Collaborative path confusion through lightweight P2P communication

The emerging location based services have brought forth a privacy risk where users expose their location information. Most of the existing solutions preserve location privacy relying on a trusted anonymizer, which may not exist in real situation. Several peer-to-peer approaches are proposed, but these techniques require large-scale data storage and communication, and they cannot provide up-to-date context information to users. To address this issue, we propose a novel method JointCache to preserve location privacy by confusing nearby users´ paths. Using this technique, users do not need to buffer context information of a large area and they only need to transfer little information to each other for cooperation. We use simulation to compare JointCache with the traditional path confusion, the results show that our technique solves the same place same time problem, and achieves higher anonymity even in a low user density situation.