Research On Information Sharing Supporting Privacy Protection In Vehicle Social Networks

With the rapid development of mobile Internet,Internet of Things and artificial intelligence,Vehicle Social Networks(VSNs),which fuse Vehicle Ad Hoc Networks(VANETs)and social networks,have become a hot research topic.VSNs,as an emerging mobile communication system,can provide users with safer,more timely and intelligent driving experience and traffic services.VSNs use a dedicated short-range communication(DSRC)protocol for one-to-one or one-to-many communication.As more and more vehicles and devices connect to the network,large amounts of security-critical and privacy-sensitive data,such as users’ identities,driving trajectories,and other private information,are generated,processed,and exchanged every day,and attacks on this private data can pose serious security risks to VSNs.In addition,in semi-trusted cloud environments,data are vulnerable to unauthorized access and tampering.Attribute-based cryptosystems can achieve fine-grained access control and ensure data security and integrity,but most schemes have high overhead in computational time complexity,resulting in high latency and cannot resist problems such as collusion attacks and attribute guessing attacks.Therefore,information security sharing under privacy protection has become an urgent problem in VSNs.In this thesis,we address the above issues and the work done is as follows:(1)A lightweight decentralized multi-authority access control scheme based on ciphertext policy attribute based encryption(CP-ABE)and blockchain is proposed.The decentralized multi-authorization node solves the key escrow problem.Vehicle users achieved rapid computing with the aid of cloud services.Aiming at the semi-trusted defect of cloud servers,by introducing blockchain to record storage and access transactions,users can self-verify and ciphertexts are tamper-proof.In addition,the improved smart contract reduces the workload of user authentication and protects user privacy with a completely hidden access policy and supports user revocation,which fits the highly dynamic nature of VSNs system and provides better flexibility.Finally,the security and performance analysis shows that this scheme has obvious advantages compared with existing schemes.(2)A distributed attribute-based encryption scheme for privacy protection is proposed,in which decentralized edge nodes jointly maintain a blockchain to solve the traditional cloud server single point of failure problem and assist users with limited resources to perform most of the computations.At the same time,all transactions and obfuscated access policies are recorded on the blockchain for audit verification,ensuring users’ control over their own data even if there are untrusted third parties.The privacy protection of users is achieved through policy hiding without pairwise operations,which increases the operational efficiency of the scheme.In addition,smart contracts are used to evaluate multiple factors such as communication range,communication time,and computation overhead of road side units(RSUs)responsible for the region,thus solving the high latency of information sharing during high traffic flow.The scheme also supports dynamic attribute updates,which provides better flexibility for the system.The security and efficiency analysis shows the feasibility of the scheme.