CROSS City: Wi-Fi Location Proofs for Smart Tourism

Abstract

The ubiquitousness of smartphones, wearables and other mobile devices, coupled with the increasing number of communications infrastructure present in smart cities, has led to the rise of location-based services. Many of these services do not verify the location information they consume and are vulnerable to spoofing attacks. Location proof systems aim to solve this by allowing devices to interact with location specific resources and later prove that they were at the location.In this paper we describe and evaluate CROSS, a system that performs location verification using techniques compatible with off-the-shelf Android smartphones. We present three strategies to produce location proofs with increasing tamper-resistance. We designed our system with user privacy and security in mind, minimizing the number of connections between devices. We implemented a prototype application to assess the feasibility and reliability of the proof strategies. The application allows rewarding users who complete a touristic route with proofs of visit collected along the way. Our evaluation, which included experiments with 30 users, showed that we can use the system in real-world scenarios, providing adequate security guarantees for the use case.