Abstract
"Intelligent Transport Systems (ITS) aims to reduce fatalities caused by road accidents
and improve traffic efficiency. Reducing accidents is a critical element that has contributed
to drawing research attention to vehicular communication systems (VCS), in
which vehicles can form a dynamic self-configuring network enabling them to communicate
with other vehicles and road infrastructure. Since road users make their actions
according to the information provided in the exchanged safety massages, received messages
should be reliable. Since the wireless communication channel is vulnerable to
attacks, an authentication scheme should be designed to meet the requirements of
such networks before any deployment. Due to the large scale of the mobile nodes and
high volume of exchanged messages in VCS and before designing a security framework
employing lightweight cryptographic operations is necessary to maintain low computation
and communication overheads. Therefore, lightweight authentication and key
management schemes are proposed in this thesis. In this thesis, there are three main
contributions.
A Lightweight Authentication Scheme for VCS Based on Timed Efficient Stream Loss-
Tolerant Authentication (TESLA) and Bloom Filters (BF) is proposed for vehicle-to-vehicle
and vehicle-to-infrastructure communications. The proposed scheme is based on
TESLA to achieve lightweight source authentication. Also, Bloom Filter (BF) is utilised
to authenticate TESLA keys instead of digital signatures. Therefore, the proposed work
focuses on reducing the usage of digital signatures to achieve higher success rate and
less overheads.
The use of digital certificates for authentication in VCS fulfil all the security requirements
but it can have a high impact on the communication and computation overheads.
Thus, a certificateless authentication framework for Vehicular Networks was proposed.
This is an enhancement of the first contribution by allowing RSUs authenticate vehicles
without the need for a digital certificate. However, a digitally signed authentication token
is used instead of digital signatures, to reduce the communication and computation
overheads while fulfilling the security requirements.
An enhanced Certificateless and Lightweight Authentication Scheme for Vehicular Communications
Systems is proposed. This work is an extension of the second contribution.
Since the performance of TESLA was shown to be suitable for VCS in the first contribution,
it is utilised in this contribution as well. Therefore, in this work employs the
lightweight authentication token with the lightweight broadcast authentication scheme
to achieve the maximum efficiency for VCS. Conventional TESLA does not support instant
authentication, which is undesired for safety-oriented applications. Future movements
of a vehicle is used to enhance the verification of messages, where each vehicle
constructs a table of the future movement prediction before a message is sent. Security
analysis has been carried out and extensive simulation of our scheme. The results show
that it can withstand a variety of attacks and has a better performance in terms of
verification delay, scalability, and communication overhead than existing schemes, and
therefore, the scheme is well suited for VCS"