The Vehicular ad-hoc network (VANET) is an important communication paradigm in modern-day
transport systems for exchanging live messages regarding traffic congestion weather conditions
road conditions and targeted location-based advertisements to improve the driving comfort. In
such environments authentication and privacy are two important challenges that need to be
addressed. There are many existing works to provide authentication and privacy in VANETs.
However most of the existing authentication schemes are suffering from high computational cost
during authentication and high communication cost during secure key distribution to a group of
vehicles. Moreover in many existing schemes there is no conditional tracking mechanism
available to revoke the misbehaving vehicles from the VANET system. In order to overcome these
issues four new approaches have been developed in this research work: Firstly a dual
authentication scheme is developed to provide a high level of security on the vehicle side to
effectively prevent the unauthorized vehicles entering into the VANET. Moreover a dual group
key management scheme is developed to efficiently distribute a group key to a group of users
and to update such group keys during the users' join and leave operations. Secondly in order
to preserve the privacy of vehicle users a computationally efficient privacy preserving
anonymous authentication scheme (CPAV) is developed to anonymously authenticate the vehicle
users based on the use of anonymous certificates and signatures. Moreover a conditional
tracking mechanism is introduced to trace the real identity of vehicles and revoke them from
VANET in the case of dispute. Thirdly an efficient anonymous authentication scheme to preserve
the privacy of RSUs is proposed in this research work: Each authenticated vehicle is required
to authenticate the RSUs in an anonymous manner before communicating with it because each RSU
provides the location based safety information (LBSI) to all authenticated vehicles when they
are entering its region. By doing this each RSU provides the knowledge to vehicle users about
the obstacles within its coverage area. Finally a computationally efficient group key
distribution (CEKD) scheme for secure group communication is proposed in this research work
based on bilinear pairing.
