Research On Data Privacy Protection Method Of Fabric Blockchain And Its Application In Parking Space Sharing

Blockchain,as an emerging distributed storage technology,can realize multi-party sharing and maintenance of data,and provide a secure and trusted environment for data sharing.However,with the gradual deepening of blockchain research in recent years,its own security issues have become increasingly apparent,and blockchain data privacy protection has gradually become a hot research topic.The Consortium Blockchain Hyperledger Fabric(referred to as "Fabric")is one of the most widely used blockchain platforms.It uses authorization to restrict nodes to access data,but it lacks a suitable solution in terms of data storage confidentiality and privacy.Aiming at the personal privacy leakage caused by Fabric users sharing transaction data and sharing smart contract code,this thesis researchs the data privacy protection method of Fabric blockchain by combining cryptographic algorithms and traditional access control technologies.First,combining the Advanced Encryption Standard(AES)algorithm and Paillier algorithm,a Fabric private data storage scheme based on hybrid encryption is proposed.The Base Chaincode,Safe Server Chaincode,and Privacy Chaincode are designed at the smart contract layer to classify and encrypt the data uploaded by users to ensure the privacy of individuals in the data storage.Through comparison experiments with existing private data storage methods,the feasibility of the scheme is proved.Secondly,combining Attribute Based Access Control(ABAC)and Discretionary Access Control(DAC),a data dynamic access control scheme based on certificate attributes is proposed.This scheme restricts user's chaincode invoke permission and transaction data access permission based on identity certificate attributes at the chaincode function level and transaction data level,the administrator can dynamically assign the chaincode invoke permission,and the data owner can dynamically set its own transaction data access permission.The feasibility of the scheme is verified by experimental tests.Finally,combining the private data storage scheme and data dynamic access control scheme proposed in this thesis to construct a parkingspace sharing system architecture based on privacy protection,the key processes are specifically designed.By implementing the basic functions of the mobile client and the web client of the system,it is verified that the proposed data privacy protection method of Fabric blockchain in this thesis has good feasibility.