Research On Privacy Preserving Scheme For Vehicle Ad-hoc Networks

The vehicular ad-hoc networks(VANETs)are the results of close integration of the new-type wireless communication technologies and the modern automotive technologies.Due to some important characteristics,VANETs are regarded as the key technologies to ensure road traffic safety and to implement the intelligent transportation system(ITS),and thus have received extensive attention from the domestic and international academic community and the automotive industry.However,VANETs are also facing serious security and privacy threats.Because VANETs are huge and open networks,attackers can eavesdrop on all the broadcast messages.In addition,a vehicle's movement trajectory is predictable,and an attacker can trace the target vehicle by analyzing the public data,thereby stealing the vehicle's private information.Therefore,the ability to effectively preserve the vehicle's private information will determine whether VANETs can be widely accepted and deployed.Based on the in-depth study of the security issues and the privacy threats of VANETs,this dissertation concludes that the privacy issues of VANETs mainly consist of the identity privacy and the location privacy.An anonymous authentication scheme based on the Blockchain technology and two vehicle location privacy preserving schemes are proposed,and the effectiveness to preserve vehicle's privacy is evaluated in different application scenarios.The main research work of this dissertation is as follows:First,the basic concepts and characteristics of VANETs are introduced.Based on the domestic and international research status,the different identity privacy and location privacy preserving schemes are compared,and the common attack models aiming at vehicle's privacy information are analyzed.The above research has guiding significance for designing the privacy preserving schemes that meet the practical requirements of VANETs.Second,a vehicle tracking attack platform is implemented to track a real vehicle.This dissertation implements a vehicle tracking platform based on the widely used privacy information attack model,and achieves high accuracy in the experiment of tracking a real vehicle.The platform has two practical implications.First,it proves that the identity privacy is a necessary but inadequate condition for the vehicle's privacy preserving.Under the premise of ensuring the vehicle's identity privacy,it is also necessary to preserve the vehicle's location information to resist the tracking attack.Second,by analyzing the influence of different parameters on the accuracy of the tracking attack,it provides reasonable ideas and theoretical basis for designing effective location privacy preserving schemes for VANETs.Third,an anonymous authentication scheme based on the extended Blockchain is proposed to meet the requirements of the identity privacy preserving for VANETs.This dissertation uses a novel data structure to extend the traditional Blockchain,proposes a new public key infrastructure(PKI)architecture,implements the certificate transparency and the revocation transparency,addresses the issues of efficiency and scalability in the anonymous authentication,thus effectively preserves the vehicle's identity privacy.Fourth,a location privacy preserving scheme is designed for the vehicular delay tolerant network(VDTN).This dissertation proposes a lightweight location obfuscating mechanism based on analyzing the characteristics of the applications in VDTN.By passing the service request between the running vehicles before submitting to the server,this mechanism effectively preserves the location information of the vehicle who sends the service request.Fifth,a location privacy preserving scheme is designed for the vehicular delay non-tolerant network(VDNTN).Due to the high real-time requirement of the applications in VDNTN,this dissertation proposes a Blockchain-based location privacy preserving mechanism.The mechanism collects and processes the location information of all the vehicles in a platoon then submits to the server,thus effectively preserves the vehicle's location privacy under the premise of ensuring the quality of service.This dissertation proposes a Blockchain-based anonymous authentication scheme and two location privacy preserving schemes for different application scenarios,aiming at preserving the vehicle's identity privacy and location privacy.The research results have important academic and application value in the privacy preserving for VANETs.