Blockchain-Based Location Proof Generation and Verification

In location-sensitive applications, service providers need to verify the location of users in order to provide them with access to a service or benefit. This provides dishonest users with an incentive to cheat on their location by submitting fake location claims. To address this issue, a number of location proof mechanisms have been proposed in literature to date. However, they are faced with different security and privacy challenges. In this paper, we utilize the unique features of the blockchain technology to design a decentralized architecture in which mobile users act as witnesses and generate location proofs for other users. In the proposed scheme, a location proof is issued as part of a transaction that is broadcasted into a peer-to-peer network where it can be picked up by verifiers for further verification. Once a transaction is successfully verified, it is stored in a public ledger. Our security and privacy analysis shows that the proposed scheme preserves users' privacy and achieves a reliable performance against Prover-Prover and Prover-Witness collusions. Moreover, our prototype implementation on the Android platform shows that the location proof generation process in the proposed scheme is faster than the current decentralized schemes and requires low computational resources.