Research On Secure Communication Protocol In VANET

With the rapid development of communication techology, cooperative vehicle infrastructure which is the new technology of intelligent transportation system has been attracting more and more attention. There is no doubt that Vehicular Ad hoc Network(VANET) is the foundation of future cooperative vehicle infrastructure technology. VANET can create a communication platform between vehicle and vehicle, vehicle and infrastructure, provide a safe and comfortable driving environment for people, it will bring about dramatic change to the traffic.However, due to the vulnerability and openness of the wireless communication,VANET is ease to be attacked, such as the message interception attack. Therefore, the development and implement of VANET must meet message confidentiality and other security requirements. And, due to the inconstancy of the network topology and other characterisyics, the current secure communication protocol for mobile ad hoc network can not apply to VANET. Therefore, in order to the operate safely, it is necessary to design a special secure communication scheme for VANET.Based on the research of domestic and foreign scholars, aim at the attack and security requirements of VANET, this paper proposed a secure communication scheme which is lightweight and scalable. The main work of this paper is shown as follows:(1) Analyzing the work which has been done by domestic and foreign scholars,based on this, proposed a secure communication scheme for VANET. The scheme divided the communication of VANET into node authentication and node communication. According to the characteristics of symmetric cryptography and asymmetric cryptographic, use asymmetric cryptographic in node authentication to ensure the legitimacy of the node, use symmetric cryptographic in node communication, and through the communication in group to realize the scalability,aim to guarantee the communication security and improve its efficiency.(2) Aim at the need of trusted center to participate in and authenticate frequently in current authentication scheme, this paper proposed an anonymous authentication protocol which is without trusted center. It realized the authentication between vehicle and road-side unit by the geographical area parameters and random authentication parameters, the process without the trusted center to participate, to reduce the cost ofthe authentication. And, propose road-side units establish the communication group by the deny negotiation, hope that reduce the steps of authenticate vehicle through the transmission of group key and improve the authentication efficiency. Finally, analyze the protocol from feasibility, security and performance. The result of analysis shows that the scheme is feasible, can meet the security requirements, and have a smaller authentication time delay.(3) Aim at the lack of scalability in current scheme and the communication requirements of different scenarios, this paper proposed a group key negotiation protocol. In this protocol, through road-side units broadcast the pseudonyms of the nodes in group and random key parameters, the nodes can communication without key negotiation. Due to this, communication overhead will not increase with the increase of the nodes’ number in the group, it is scalable. And, according to the requirement of the different scenarios, this paper designed a broadcast communication protocol, the point to point communication between vehicles protocol and the communication between vehicle and road-side unit protocol. Finally, analyze the scheme from security and performance, the result shows that the protocol can meet the security requirement of VANET communication, and make simulation experiment on the protocol by NS2, the result shows that the scheme is superior to other schemes on communication overhead and the average dely.