Study Of Privacy-preserving Authentication And Access Control Based On Group Signature In VANETs

As an important part of intelligent transportation,VANETs improve driving safety and driving experience by providing high-quality and personalized services.Vehicles upload the real-time road conditions collected while driving to the VANETs platform.The transmitted data contains information such as vehicle identity,location,and speed.In a network environment with open channels,it is easy for attackers to intercept and modify the data,as well as analyze its content to infer the user’s privacy.Meanwhile,attackers spread false information in the network,leading to traffic accidents and other public safety incidents.With the further development of VANETs,the proliferation of in-vehicle applications,and the exponential growth of data volume,the existing VANETs framework can no longer meet the requirements of low-latency services.Considering that the content transmitted by the platform to the vehicle can only be obtained by the vehicle which sent the request and cannot be recovered by other legitimate vehicles and attackers,it makes higher demands on the computation and storage capabilities of the VANETs platform.In this thesis,we propose corresponding solutions to the above problems,with the following main contributions:(1)To address the security challenges of user identity information in VANETs,this thesis proposes an efficient,privacy-preserving authentication scheme with on-chain certificate management.First,we achieve secure and lightweight mutual authentication between vehicles and RSUs through elliptic curve cryptography and exclusive-OR operations.Second,to ensure the transparency of certificate issuance and revocation,we design a blockchain architecture that can accommodate counting garbled bloom filter.The group signature algorithm in the certificate acquisition process ensures the anonymity and traceability of vehicles.Besides,we propose a non-forgeable and nonrepudiable billing mechanism based on hash chain technology to resolve disputes arising from the payment process.(2)To address the shortcomings of traditional VANETs architecture with slow processing speed and high service latency,we introduce mobile edge computing and propose a revocable access control scheme with fair incentives.First,we construct a secure group signature algorithm with formal proofs of correctness,anonymity,traceability,and non-frameability to ensure anonymous authentication and conditional revocation during content delivery.Meanwhile,considering that access control can still be achieved even if the content provider is offline during content delivery,we design a proxy re-encryption algorithm to implement the first layer of access control,which can perform update operations with the help of edge nodes.In the second layer of access control,the requested vehicles are decrypted correctly with the help of edge nodes,while the edge nodes record the relevant data to reward the vehicles with cache hits.(3)Finally,the two schemes proposed in this thesis are implemented on the NS2 and ndn SIM platforms,respectively.The security analysis and experimental results show that the proposed schemes can achieve security and privacy protection of the authentication process and content access control mechanism with low computational and communication overheads.This thesis contains 15 figures,8 tables and 89 references.