Using Block Chain for Peer-to-Peer Proof-of-Location

Location-Based Services (LBSs) build upon geographic information to provide users with locationdependent functionalities. In such a context, it is particularly important that geographic locations claimed by users are the actual ones. Verification approaches proposed in the last few years are not satisfactory, as they depend on a centralized infrastructure that entails a high risk to the privacy of users. In this paper, we present a novel approach for producing proofs-of-location, i.e., digital certificates that attest someone’s presence at a certain geographic location, at some point in time, whereby LBSs can validate user locations. In particular, our approach relies on the block chain — mostly known for being Bitcoin’s core technology — to design a completely decentralized peerto-peer architecture that guarantees location trustworthiness and preserves user privacy, at the same time. 1998 ACM Subject Classification C.2.4 Distributed Systems