Research And Implementation Of A Data Sharing Method Based On Attribute-based Encryption In IoV

The Internet of Vehicles(IoV)can connect vehicles,pedestrians,and infrastructure etc.to form a network of mutual cooperation.IoV can optimize traffic resources,reduce traffic accidents and improve user experience,and these advantages come from the data sharing of vehicles in IoV Vehicles are able to collect information about nearby traffic conditions and their own driving states,and share the data with other vehicles and traffic management centers.This can help other vehicles make decisions and optimize trafic flow.However,the dynamic and open nature of IoV makes user data vulnerable to attacks and the security of data sharing cannot be guaranteed.To ensure the security and fine-grained access control of data sharing in IoV,in this thesis we study the sharing of data through Attribute-based Encryption(ABE)technology.ABE is a new type of public key encryption technology,whose encryption process requires the formulation of access policies related to attributes,and decryption also requires the matching of access policies with user keys.Compared with traditional encryption techniques,ABE can achieve one-to-many encryption and fine-grained access control.However,several special problems need to be solved in the IoV environment in order to apply ABE in the IoV,such as the difficulty of revoking the frequent changes of attributes due to the high-speed mobility of vehicles,the privacy leakage of access policies due to the privacy sensitivity in the IoV,and the possible lack of computing power of individual vehicles in the IoV.In order to solve the above problems,this thesis concentrates on the improvements to the attribute-based encryption scheme.The main work is as follows.(1)A blockchain-assisted encryption scheme with flexible revocable attributes is proposed in order to solve the problem of difficult revocation of frequent attribute changes due to the mobility of IoV.The proposed scheme uses a blockchain instead of a trusted center,which solves the problem of excessive pressure on trusted authority and enhances the transparency of the system.In addition,the scheme uses a user binary tree and system updates to achieve attribute revocation,and the execution of the revocations are decided based on the states of the binary tree.Finally,the proposed scheme was evaluated by simulation.The results show that compared with the existing schemes,the proposed scheme has a lower overhead under the condition of a large number of revocations.(2)In response to the problem of privacy leakage of access policies and the lack of single-point computing power in a single node,,an attribute encryption scheme that can be fully outsourced with policy hiding is proposed.The scheme uses customized policy hiding.Users can hide some attributes in the access policy according to their privacy preferences,which protects the sensitive privacy of users with low overhead.In addition,the scheme achieves full outsourcing,which allows the key generation,encryption and decryption processes to be outsourced to third-party nodes.Finally,the proposed scheme was evaluated by simulation.The simulation results show that proposed scheme reducing greatly the local computation and improving the efficiency of the scheme.