Research On Key Management Scheme In Vehicular Ad Hoc Networks

Intelligence has become the mainstream trend in the development of transportation system in the future.As the foundation of Intelligent Transportation System(ITS),the security of Vehicular Ad Hoc Networks has become the main obstacle in the development of ITS,especially the communication security issue of Vehicular Ad Hoc Networks.This paper mainly studies the security of key management in the group communication of Vehicular Ad Hoc Networks through analyzing the characteristics of Vehicular Ad Hoc Networks and combining the research results of the traditional Mobile Ad Hoc Networks.This paper proposed a self-healing key distribution scheme based on hash chain and an authenticated dynamic key agreement scheme for the two main group communication modes: V2I(Vehicle-to-Infrastructure)and V2V(Vehicle-to-Vehicle)in Vehicular Ad Hoc Networks.The main contents of this paper are as follows:(1)For the characteristics of V2 I communication mode in Vehicular Ad hoc Networks,a self-healing key distribution scheme with dynamic revocation based on hash chain is proposed.There exists many problems in Vehicular ad-hoc network,such as the unstable network and high packet loss rate.The traditional key distribution scheme based on bidirectional hash chain will generate a large amount of information redundancy while achieving self-healing.This paper introduces a self-healing hash chain and make it possible that the vehicle node can still recover the lost group session key without sending extra messages by the group manager,after losing the key update packet,and it reduces the information redundancy effectively.In addition,this paper realizes the dynamic revocation of malicious vehicle nodes during a session by combining the self-healing hash chain with the revocation polynomial.(2)For the characteristics of V2 V communication mode in Vehicular Ad hoc Networks,this paper proposes an authenticated dynamic key agreement scheme based on identity authentication.In Vehicular Ad Hoc Networks,the vehicles join or leave out a communication group frequently,which leads to update the keys frequently and the key update process of traditional key agreement schemes is cumbersome,which is not suitable for high dynamic Vehicular Ad Hoc Networks.This paper improves the key update process by distinguishing whether it is a malicious vehicle node or not.Only when a malicious vehicle node is revoked,the scheme needs to be re-executed.For the joining and leaving of the legitimate vehicle node,it only needs to select a representative node in the communication group and update the group session key based on the original one.The improvement effectively reduces the number of repetitive execution and the communication overhead of the proposed scheme.This paper has conducted a security analysis and performance analysis for the proposed key management schemes.The security analysis shows that the proposed two key management schemes have a variety of security features,which can meet the security requirements of Vehicular Ad Hoc Networks.The performance analysis show that comparing with the existing key management schemes,the proposed schemes can effectively solve the dynamic change of the vehicle nodes in communication group,reduce the communication cost,and is more suitable for Vehicular Ad Hoc Networks.