An Identity Privacy Protection Scheme Based On Pre-Negotiated Secret In VANETs

In the vehicle ad hoc network(VANETs),vehicles communicate through wireless channels,which leads to many security problems in VANETs.Without security and privacy guarantees,an attacker can track any vehicle they are interested in by collecting and analyzing traffic information broadcast by the vehicle.In addition,when a car publishes false information on the network,it has a very negative impact.The certificate center must be able to reveal the true identity of the malicious vehicle and make corresponding punishment measures.In VANETs,the frequency of message transmission is high.To ensure its reliability and real-time performance,there is a relatively high requirement for message authentication time.In view of the privacy leakage and message authentication problems in VANETs,this thesis proposed an anonymous authentication scheme based on pre-negotiated secret.This scheme is based on the pseudonym to achieve anonymity.Each vehicle has a unique identity.In the communication,a short-term pseudonym certificate has been obtained through the TA certification in advance to prove its legal status.The vehicle negotiates a communication authentication key with each neighboring vehicle through a pseudonym certificate,and then based on the communication key,the signature and the verification can be realized by a simple and fast HMAC.For the location privacy protection,this thesis proposed a pseudonym replacement scheme based on beacon message retransmission,in which the vehicle establishes a mix zone through dynamic coordination,and avoids being tracked by the global attacker in the form of beacon message retransmission in the mix zone.The vehicle’s trajectory is private and secure.This thesis analyzed the overhead and efficiency of the message authentication scheme,and the efficiency was improved compared with the traditional scheme.In this thesis,the pseudonym transformation scheme was implemented in the simulation environment,and compared with the previous schemes,the effectiveness of the scheme is proved.