An Efficient and Privacy-Preserving Information Reporting Framework for Traffic Monitoring in Vehicular Networks

Traffic monitoring services show great potential for improving traffic efficiency in vehicular networks. With the assistance of 5G innovation, vehicles can report information such as driving misbehavior and traffic status to the traffic monitoring server which then returns feedback to the network to enhance the efficiency of traffic management. However, some challenging issues in information reporting need to be addressed first. Trivial reported information significantly increases the workload of the server. Moreover, a server is difficult to distinguish the truth of reported messages. As a result, the server is incapable of returning immediate feedback to the network, thereby reducing the quality of traffic services. Meanwhile, uploading location-based information to the server exposes vehicles' privacy. Although some existing techniques such as trust management benefit information reporting, a complete framework is still missing. In this paper, we propose an information reporting framework for solving both efficiency and privacy issues. Specifically, messages are probabilistically reported to the server depending on their importance. Furthermore, the DAG-based blockchain ensures that messages reported for a specific event are all gathered in the same ledger. We also present a scheme based on the geo-indistinguishability to protect the location privacy of vehicles. Extensive experiments demonstrate that the proposed framework preserves the location privacy of vehicles and achieves efficiency with acceptable overheads.

I. Introduction

The emergence of Intelligent Vehicles (IVs) shows great potential for improving traffic efficiency in vehicular networks. Equipped with on-board units (OBU) and a variety of sensors (e.g., multi-beam lidars and high-resolution cameras), IVs can sense the surrounding environment [1], [2] and receive messages from neighboring vehicles [3]. Moreover, 5G as a promising technology is gradually being applied to IVs, enabling them to communicate directly to the cloud server [4]. For instance, a vehicle could report a message to the server with overspeed evidence of a neighboring vehicle, or an urgent event (e.g., “There is an accident on road A!”). The server aggregates all messages for a specific event and figures out the credible one based on the honest majority that a majority of messages sent to the server are honest [5]. It then notifies other vehicles in the network about upcoming traffic situations and potential risks to enhance traffic safety and road efficiency.