An Efficient Cooperative Message Authentication Scheme in Vehicular Ad-hoc Networks

Real-time applications play a significant role in the area of VANET, and are mainly required for these kinds of networks. On the other hand, when the number of messages received by vehicles increases in the network, then the applied computation load becomes extremely high and consequently, delay on the message authentication process significantly increases. This paper is presented with the aim of introducing a novel cooperative message authentication (CMA) scheme for VANET, the main purpose of which is alleviating the computation load on vehicles while verifying messages by using two-part identity-based signature. The scheme enables vehicles to verify only a limited number of the total received massages, and uses other vehicles' authentication results for the rest of the messages. The security arrangements to prevent the free riding attacks have also been considered. Our CMA method uses batch verification and does not use pairing operation and public key certificates. Therefore, our proposed CMA scheme achieves considerably low computation load compared to the related works. Performance evaluation and comparison results of the computational complexity show the efficiency, practicality and deployability of our proposal.