Secure VANET Authentication Protocol (SVAP) Using Chebyshev Chaotic Maps for Emergency Conditions

It is crucial to support emergency applications provided by vehicular adhoc network (VANET) through enabling vehicles to quickly access to the infrastructure and consequently request rescue services. Additionally, the communication channels between vehicles and the infrastructure lack various security features due to the inferior wireless characteristics of their environment. However, most of the existing authentication schemes which are used to fix the security drawbacks lead to heavy computations and large storage burdens on the vehicle onboard unit (OBU). These schemes utilize secure channels while distributing the network parameters between the various participants. Yet, it is not efficient to establish secure channels during the interactions between entities. Furthermore, lightweight cryptography is an efficient security solution which is adequate for OBU to maintain a reasonable efficiency with low computational and communication costs. Two basic demerits for lightweight authentication protocols are highlighted as follows: Firstly, symmetric key-based authentication protocols dismiss achieving non-repudiation feature, leading to several security attacks in VANET. Secondly, public key-based authentication schemes are relied on elliptic curve cryptography (ECC) which makes the protocol implementation more difficult. Hence, this paper introduces a novel authentication protocol that utilizes Chebyshev chaotic maps to secure connectivity between the vehicles and infrastructure without using secure channels to distribute the network parameters. The new protocol combines the concept of the symmetric key cryptography with the public key signature to satisfy both the lightweight property and non-repudiation feature. Thus, this protocol introduces a novel network model which is the lowest hardware complexity, compared with others. The performance analysis is performed by Wolfram Mathematica, proving that the proposed protocol is superior in terms of security and performance aspects; its computation and storage costs of OBU are enhanced with 24.09% and 16.99%, respectively, compared to the most competing scheme. Besides, the Scyther simulation confirms the security of the protocol.