Peer-to-Peer Location-Based Services based on Blockchain and Web Technologies

A distinctive feature of smart cities is the fruitful and effective interconnection among mobile users and resources, to support the fulfillment of sophisticated location-based services (LBSs). LBSs are increasingly taking advantage of user geographic location to provide a broad range of applications, such as traffic monitoring, social networking, emergency management and advertising. Unfortunately, most LBSs rely upon centralized infrastructures, thus raising, besides scalability and resilience, also serious concerns regarding user privacy. This Ph.D. Thesis presents a new peer-to-peer overlay scheme suitable for the development of LBSs, enabling efficient peer and resource retrieval around any geographical location, while paying attention to users' privacy. An important difference between the designed peer-to-peer overlay and other solutions in literature is the capability to adapt the topology of the network depending on peers' mobility. Throughout this Thesis, the designed peer-to-peer overlay has been intensively evaluated, both through simulations in various and different scenarios of mobility, and by means of field testing performed with the collaboration of several volunteers. Furthermore, the Thesis presents a real implementation of the peer-to-peer overlay which is released online with a free and open source software license, thus making it usable as a web application framework without restrictions. Finally, this Thesis faces the problem related to truthfulness of geographical locations stated by peers, proposing a privacy-aware approach inspired by the novel blockchain technology. Simulation-based evaluation of the proposed technique shows an effective and robust behavior even in presence of significant shares of deceitful peers.