Research On Efficient Anonymous Authentication And Group Key Agreement Scheme In VANETs

As an important part of the next-generation intelligent transportation system,VANETs is a promising way to solve current road traffic problems.The fast information exchange in the VANETs system are realized by equipping the vehicle with a communication unit and deploying basic communication facilities on the roadside.In this way,VANETs can provide vehicles with real-time traffic information,safety information,and entertainment information to ameliorate traffic conditions.As a special mobile adhoc networks,there are a number of network threats in VANETs.In order to ensure security and privacy,it is necessary to authenticate the legitimacy of sender and the source of message.Considering the limitations of network bandwidth and computing performance,it is also need to improve efficiency as much as possible.Aiming at problems mentioned above,research on the anonymous message authentication and key agreement protocol in VANETs have been carried out and two schemes have been proposed in this thesis.Main contributions of this thesis are as follows:(1)A completely anonymous authentication scheme based on short-term certificates has been proposed.In this scheme,the vehicle uses a short-term key to generate a corresponding short-term certificate for each session.Short-term certificate contains authentication information and message signing.When malicious behavior occurs in the network,TM can track the abnormal vehicle efficiently.In this scheme,bilinear paired signature operation is used only once to realize the authentication of the information source.In addition,a privacy information authorization and sharing algorithm is proposed in this scheme to protect the most important sensitive privacy information of each vehicle.Formal security of this scheme is analyzed through BAN logic.Analysis on computational efficiency and communication overhead of the scheme are carried out with simulation.The results show that the scheme can meet the performance requirements of VANETS while ensuring security.(2)A group key agreement scheme based on chaotic mapping has been proposed,which is composed of identity authentication and key agreement.With the semi-group property of Chebyshev chaotic map,one-time key is designed to realize the real-time replacement of user password,authentication information and vehicle pseudonym,which improves the security and anonymity.An efficient key agreement protocol is proposed,in which the group session key is used to achieve message authentication between vehicles.Benefiting from adopting Chebyshev chaotic map instead of bilinear pairing and elliptic curve,efficiency of calculation and communication of this scheme is improved obviously.The formal security proof and security analysis are carried out,as well as the computation and communication overhead of this scheme are analyzed.Results show that this scheme achieved outstanding security and performance.