Designing a Privacy-Aware Location Proof Architecture

Abstract

Although location-based applications have existed for several years, verifying the correctness of a user's claimed location is a challenge that has only recently gained attention in the research community. Existing architectures for the generation and verification of such location proofs have limited flexibility. For example, they do not support the proactive gathering of location proofs, where, at the time of acquiring a location proof, a user does not yet know for which application or service she will use this proof. Supporting proactive location proofs is challenging because these proofs might enable proof issuers to track a user or they might violate a user's location privacy by revealing more information about a user's location than strictly necessary to an application. In addition, none of the existing architectures possesses an effective cheat detection mechanism to spot users who cheat about their location. We present seven essential design goals that a flexible location proof architecture should meet. Furthermore, we introduce a lightweight location proof architecture that realizes a subset of our design goals and that includes user anonymity and location privacy as key design components, as opposed to previous proposals. We then present a complete architecture that meets all of the design goals and demonstrate how some of the design goals can be achieved by adopting proper cryptographic techniques. Note that the reason of having a lightweight architecture that meets a subset of our design goals is explained in section 2.4.6. Finally, we provide an implementation, experimental results and a deployment strategy of our location proof architecture, and present three real-world location-proof-based applications to further demonstrate the practicality of our architecture.