Trust Management Scheme Based on Hybrid Cryptography for Secure Communications in VANETs

Vehicular Ad hoc Networks (VANETs) are used to improve traffic management and reduce the number of road accidents by providing safety applications. However, VANETs are susceptible to a number of security attacks from malicious entities. To secure the network against these attacks, most of the researchers have proposed various security schemes based on cryptography and trust management. While both cryptography and trust management are effective to some extent, each scheme has some flaw to fully secure the network. In this paper, we propose a trust management scheme based on hybrid cryptography (TMHC) to secure VANET to a larger extent. As authentication is an integral part of trust establishment and secure communications between vehicles, the proposed TMHC integrates hybrid cryptography based authentication for efficient and robust trust management scheme. The hybrid cryptography includes, asymmetric identity-based (ID-based) digital signature and symmetric hash message authentication code (HMAC). The trusted road-side unit (RSU) evaluates trust-value, whereas, agent trusted authority (ATA) computes trust-value of vehicle based on its reward-points. The results are gained with extensive simulations to validate the proposed scheme. The results show that the proposed scheme meets security requirements and performs effectively. The communication overhead, computation overhead, storage overhead, and end-to-end delay of the proposed scheme were improved by 6% to 15%, 9% to 23%, 7% to 19%, and 4% to 15.85%, respectively, as compared to existing schemes.