Improving scalability in vehicular communication using one-way hash chain method

Improving road safety and optimizing road traffic relies on both Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications. The successful deployment of vehicular communication depends on the two contentious factors, security and privacy. Though several researches have been conducted on the issuance of pseudonyms to deal with these issues, the traditional PKI based schemes used for the generation of these pseudonyms produce an enormous signing and verification costs. In order to address this problem, we propose a novel scheme in which the RSUs in a VANET use a one-way hash chain scheme to generate a series of public/private key pairs and to distribute them along with an n   bit hash code H^ and a proof cipher C^ to the vehicles in its range. Since the RSU will provide a synchronized clock to all vehicles, anytime a vehicle can verify another vehicle by combining the vehicle’s public key and its n bit hash code, which should prove the same cryptographic hash function of the receiving vehicle. Through this proposed Hash-chain based Authentication Protocol (HAP), the certificate costs of messages are immensely reduced. Moreover, if an attacker tries to compromise a node’s public key it will be infeasible for him/her to achieve the desired task, as the vehicle frequently changes its public/private keys in a random fashion and hence guarantees a secured vehicle communication. We analyzed the proposed protocol extensively to validate its better performance when compared to its counterparts.