Abstract
Research into the established area of Intelligent Transportation System (ITS) is still evolving and fast-moving fuelled in part by rapid changes in vehicular technologies and mobile communication network. A practical challenge is that many vehicular communication applications and services make use of the Basic Safety Messages that contain the vehicle location and other personal data. A popular way of dealing with this privacy issue is to utilise a pseudonym change scheme to protect the vehicle’s identity and location. However, many such schemes suffer from poor scalability and the certificate management difficulty raises with the number of pseudonyms generated and stored in the ITS system, casting doubt of the economic feasibility of such approaches. In this thesis, firstly, Cooperative Pseudonym Change Scheme (CPCS) for VCS is proposed for providing high level of anonymity. In this model, the Road Side Units (RSUs) is the key factor by storing generated pseudonym sets from the Trusted Authority (TA), then delivering sets of pseudonyms to vehicles which has similar context. Secondly a Decentralised Pseudonym Management System (DPMS) Using Distributed Ledger Technology is proposed to overcome limits that CPCS and most other pseudonym change schemes of low scalability and high cost of managing large numbers of pseudonym certificates in ITS. This scheme consists of pseudonym distribution and a shuffle operation, allowing the re-distribution and re-usage of existing pseudonyms by different vehicles. The results demonstrate that the proposed scheme achieves a better degree of anonymity and low request delay at a lower cost than existing schemes. Thirdly a Distributed Pseudonym Certificate Revocation Scheme (DPCRS) for VCS is proposed based on the framework that DPMS introduced. The proposed scheme embeds part of the certificate revocation functions within the security and privacy applications, aiming to reduce the communication overhead and shorten the processing time cost. Extensive simulations and analysis show the effectiveness and efficiency of the three proposed schemes.