||Studies were conducted on vehicular ad-hoc network (VANET) in recent years. VANET is a network that combines on-board wireless equipment and roadside fixed wireless equipment through wireless communication technology. In this environment, each vehicle can broadcast messages to other vehicles and inform drivers to change the correct route in order to enhance the efficiency of driving and to avoid accidents. Since vehicles communicate through wireless tunnel, many malicious attacks may occur during the transmission of messages. Therefore, ensuring the correctness of receiving messages and verifying the authenticity of the sender is necessary. Besides, we also need to protect the real identities of vehicles from revealing to guarantee the privacy. When vehicles broadcast messages, we usually use RSU to do message authentication that we can ensure messages integrity and broadcast messages by legitimate vehicles, rather than by the attacker’s malicious forgery.|
Vehicle’s identity verification and message authentication can be done through the help of RSU. According to cover range of RSU has limit, most of RSUs will be set on street lights or traffic lights which can provide electric power and network.In this paper, we propose the mechanism based on chameleon hashing and HMAC to do identity verification and message authentication under the environment without RSU.
In our system, the secret value is retained by TA and TA will use its own secret values to calculate the chameleon hash value and pre-load the hash value and secret values to vehicles. The other vehicles can also verify the chameleon hash value to authenticate the security source. Besides, unlike methods of traditional anonymous authentication, we also combine chameleon hashing with Diffie-Hellman technologies to enhance performance for private communication. The method of our proposed is more think about how to combine theoretical and reality that not only overcome problems of related literature, but also meet the required safety of VANET.