  With the increasing development of advanced communication technologies,
vehicles are becoming smarter and more connected. Due to the tremendous growth
of various vehicular applications, a huge amount of data is generated through
advanced on-board devices and is deemed critical to improve driving safety and
enhance vehicular services. However, cloud based models often fall short in
applications where latency and mobility are critical. In order to fully realize
the potential of vehicular networks, the challenges of efficient communication
and computation need to be addressed. In this direction, vehicular fog
computing (VFC) has emerged which extends the concept of fog computing to
conventional vehicular networks. It is a geographically distributed paradigm
that has the potential to conduct time-critical and data-intensive tasks by
pushing intelligence (i.e. computing resources, storage, and application
services) in the vicinity of end vehicles. However secure and reliable
transmission are of significant importance in highly-mobile vehicular networks
in order to ensure the optimal Quality of Service (QoS). In this direction,
several authentication mechanisms have been proposed in the literature but most
of them are found unfit due to absence of decentralization, anonymity, and
trust characteristics. Thus, an effective cross-datacenter authentication and
key-exchange scheme based on blockchain and elliptic curve cryptography (ECC)
is proposed in this paper. Here, the distributed ledger of blockchain is used
for maintaining the network information while the highly secure ECC is employed
for mutual authentication between vehicles and road side units (RSUs).
Additionally, the proposed scheme is lightweight and scalable for the
considered VFC setup. The performance evaluation results against the existing
state-of-the-art reveal that the proposed scheme accomplishes enhanced security
features.
