title: A Pseudonym-based Solution for Efficient Security and Enhanced Privacy in VANET Safety Applications
Creators: name: Al-Ani, R
Publisher: name: Liverpool John Moores University
Year: 2022

description: In Vehicle Ad-hoc NETworks (VANET) safety applications, vehicles are required to exchange messages periodically at 1-10 Hz with nearby vehicles (within 300 meters) wirelessly and in plain format. The exchanged message usually contains the state of vehicle such as its current location, speed, and direction, as well as the state of roads such as icy road, closed road, traffic jams, an accident on the road, etc. With such support, the contextual awareness of the drivers about their surrounding environment would be improved. Thus, the road safety would be significantly improved because of a potential accident can be prevented in advance. The security of the exchanged messages is a paramount requirement because an accident, injury, or even loss of life could be a direct consequence of malicious notification. Moreover, eavesdroppers can collect the exchanged messages and track the individual driver’s whereabouts by linking subsequent messages for a period of time. Thus, the location privacy of the driver must be properly protected to obtain the public acceptance of these applications. Current standardisations and research efforts have mainly nominated the use of pseudonyms, rather than real-identities, based on Public Key Cryptographic (PKC) to provide an acceptable balance between security and privacy. The public key is excluded from any identification information and used as a pseudonym. This pseudonym must be certified by a trusted authority who can verify it later in the case of a dispute. Moreover, with the amount of information that a vehicle is required to broadcast in these applications, the pseudonym must be changed over time to avoid the long-term linkability of the vehicle via its locations. A simple pseudonym changing scheme is ineffective to prevent tracking the vehicle based on its locations. Thus, III many researchers have been working on designing more effective schemes but very few of them have considered the impact of such schemes on safety applications. Therefore, in this thesis, we aim to design a novel scheme for VANET safety applications that can achieve efficient security and enhance the privacy level without compromising safety. First, the main requirements of these applications were specified, and the state-of-the-art schemes were reviewed. Then, two schemes have been proposed: 1) the Safety-related Privacy Scheme (SRPS) was mainly aimed to reduce the impact of enhancing privacy level on safety, and 2) the Hybrid-based Pseudonym Changing Scheme (HBPCS) was mainly aimed to reduce the impact of security overheads on safety. To evaluate the efficiency of the designed schemes, we implemented these schemes using a combination of four simulators and then compared them quantitatively with the other five selective schemes from the literature (CAPS, PPC, RSP, CSP, and SLOW). The experiment results have shown that the SRPS can achieve the best balance between the three key issues (security, privacy, and safety) but its efficiency decreased in traffic jams, which has been addressed by the HBPCS.