A Cross-Layered Approach Based Optimization for Secure and Reliable Routing in VANETs

The Vehicular Ad-hoc Networks (VANETs) have the potential to bring a significant breakthrough in the domain of Intelligent Transport Systems (ITS). However, the deployment of the VANETs is still in its infancy due to the challenges faced in ensuring security and reliable routing of the information. The trust based routing models can be recognized as a lightweight alternative to the computationally extensive cryptography based traditional security solutions in VANETs. Since the impairments due to the unpredictable wireless medium are imminent, a trust model must be designed by taking into account the real-world implementation issues, such as channel effects while routing. Hence, in this work, a novel trust based model assigns a trust score to the nodes based on their consistent performance in the network and the channel conditions at the instant of transmission to prevent the coarse-grain trust revocation of the innocent nodes. A novel routing optimization algorithm has been designed by employing a modified Remora optimization algorithm that ensures security and general QoS by considering parameters like the trust score of the node, its residual energy, SINR, and link quality. The proposed approach makes prudent decisions under varying node densities and attack ratios, hence adapting well to the dynamic VANET scenario. The simulation results prove the efficacy of the proposed approach in terms of efficient True Positive Rate (TPR), low False Positive Rate (FPR) under varying attack ratios and node densities, and improved PDR, average throughput, and end-to-end delay as compared to the standard trust based models and considered optimization algorithms.