Research And Implementation Of Privacy Preservation Scheme Of Electronic Health Records Based On Blockchain

Electronic Health Records(EHR)have been widely used in cloud-based medical platforms,which includes patient’s privacy data.Patients and hospitals are the owners and managers of the electronic health records,respectively.Therefore,the separation of ownership and management of electronic health records leads to the risk of leakage and abuse when electronic health records are stored in the cloud-based medical platforms.Thus,it is particularly important to explore new privacy preservation schemes for electronic health records storage.Due to the features of decentralization,immutability,and traceability,blockchain technology is a promising way to play an important role in the privacy preservation of electronic health records.The contributions of this thesis are listed as follows:(1)Describe the application scenarios of electronic health records,investigate the state-of-the-art methods applying blockchain technology to protect the privacy of electronic health records,and refine the demand of cross-chain technology for the circulation of electronic health records between different hospitals.The roles and functions involved in electronic health records in cross-chain scenarios are analyzed and designed,and a cross-chain electronic health records architecture based on the Polkadot relay chain is proposed.(2)An electronic health record privacy preservation scheme based on blockchain cross-chain technology(CEPS)is proposed.An electronic health record cross-chain process based on Polkadot is given.Security analysis of the scheme is demonstrated from three aspects,including 51% attacks,dishonest nodes,and malicious collusion.We adopt Substrate as the blockchain development framework,combine Node.JS,React and WebAssembly technologies together,then implement the CEPS solution cross-chain system from three levels: the application layer,the data layer,and the blockchain layer.(3)The layout of the electronic health record cross-chain system was demonstrated.We establish the Substrate blockchain test environment,carry out the functional testing on the generation of electronic health record account and block,as well as the addition and deletion of records.The performance is tested in two aspects,namely,block production speed and communication costs.And the effectiveness of the proposed scheme for the privacy preservation of electronic health records is verified.This thesis applies the cross-chain technology to the privacy preservation of electronic health records,realizing trusted sharing of patient electronic health records across different hospitals.Then the patient medical treatment could be more cost-effective.It will be beneficial to promoting the variation from hospital-centric to patient-centric in the medical field.