Research On Privacy-preserving Mechanism For Vehicular Ad-hoc Networks

To reduce traffic accidents and improve driving experience, extensive efforts have been made by industry and academia. And so, a self-organized vehicular ad-hoc networks emerged. Through inter-vehicle communication and vehicle to on board unit communication, VANETs can collect traffic and road information and deliver them to all the users after integration. At present, one of the key issues in designing and carring out VANETs is anonymous authentication and privacy protection. On the one hand, we expect that a message is authenticated by a trusted vehicle instead of malicious or bogus vehicle. On the other hand, the sender is reluctant to leak its identity or location information during the authentication. Clearly, the goals of privacy presentation and accountability seem conflicting. Technically, the conditional privacy protection should not be abused where an involved vehicle should be revoked just in a signature dispute.This thesis focuses on how to solve the conditional privacy-preserving communication problems in VANETs. By analyzing the existing proposals, two kinds of schemes are given in this thesis. The main content of this thesis includes the following aspects:1. Propose a kind of privacy-preserving communication protocol in VANETs. In this scheme, the vehicle nodes generate anonymous certificate under RSU's help whenever it wants to update an anonymous certificate or all the certificates expire. In this scheme, identity authentication and certificate issue are taken by Transportation Regulation Center and Roadside Units respectively. In addition, this proposal also gives the certificate revocation scheme in which the certificate has not expired yet and the tracking scheme. Finally, the security analysis and performance analysis are given.2. Propose a kind of privacy-preserving communication protocol in VANETs based on conditionally anonymous ring signature. This thesis gives a concrete implementation of the algorithm, including anonymous communication and tracking schemes. Specially, the tracking algorithms do not depend on the Transportation Regulation Center and Roadside Units. Finally, the security analysis and performance analysis are given.3. Simulate IEEE 802.11 p protocol by using NS2 and SUMO tools. The analysis of get ratio, delay and throughput capacity regarding to different vehicle number are given.