A Lightweight Group-based Secure Authentication And Communication Scheme In VANETs

VANETs security has long plagued the development of the IoT industry.Because of the wireless communication in VANETs,it is vulnerable to hackers,which will bring serious security problems.Public certificate methods,ID based methods,group-based encryption methods etc are widely used in this area.Among them,group signature is widely used and can effectively speed up authentication and protect users' privacy.In order to reduce the computation and communication overhead in traditional methods,this thesis designs a lightweight hash-based and HMAC-based authentication protocol between different entities in VANETs.This thesis takes the advantage of group communication,in which RSU plays the role of group manager.After the group members get the group key,this thesis proposes a symmetric HMAC-based V2 V communication protocol.This method will greatly improve V2 V communication speed.This thesis also designs a dynamic time slot group key management,in which,time is divided into intervals,and each interval has a different group key.If the vehicle has an urgent desire to communicate,it can send a request to RSU,then RSU will judge the urgency and other factors of messages,and decide whether to trigger a new group key update at once.This will achieve a balance between reducing communication overhead and ensuring communication efficiency.In experiments,this thesis first analysis the security performance in this protocol,second,compares the computation cost and communication cost of proposed authentication solution with other solutions.Third,this thesis compares the dynamic slots solution's communication overhead with other solutions,and simulates random vehicle group key request to calculate the average waiting time of the requesting vehicle under different vehicle densities.The results show that the scheme achieves good performance in communication overhead and efficiency.The protocol is also practical.