Research On Blockchain-based Medical Data Sharing Scheme

Today,with the development of medical data in the direction of multi-agency collaboration,the need for management of own personal medical records is raised.As Electronic Medical Records(EMR)contain sensitive personal information,more attention must be paid to data security and privacy protection.As an important part of medical information construction,the rational use of EMR for individuals,can provide patients with better precision treatment and reduce treatment expenses.While for the community,it can play a role in improving medical standards and drug development.How to achieve the interconnection of medical institutions,integrate the EMR and provide management and sharing solutions for patients have become hot research issues in medical scenarios.Cloud computing provides a solution for this scenario that patients can achieve quick and convenient access to his EMR by the cloud server.There are risks of data leakage and singlepoint-of-failure in cloud storage.As patients stores all medical records in the cloud,it will cause great losses to patients when malignant events occurs.With the frequent occurrence of data leakage incidents,people’s trust in cloud service providers has gradually decreased.The introduction of blockchain has provided new ideas for data sharing in medical scenarios.Blockchain can integrate patients’ EMR while retaining the decentralized storage method,and solve the "Information Isolated Island" problem in medical scenarios.This thesis mainly studies the issue on how to balance the confidentiality and usability of EMR,share medical data while preserving patients’ privacy.The main contributions are as follows:1.This thesis proposes a blockchain-based accountable medical data sharing scheme.As the access parties are divided into areas and the access control strategies are formulated according to the characteristics of each area,the scheme realizes safe sharing of medical records while preserving patients’ privacy and exerts the role of medical data to both individuals and communities.The traitor tracing technology and the accountable attribute-based encryption are used in the scheme to achieve the tracking of illegal sharing behaviors.We also use the blockchain technology to store the digest information of the medical record in a public ledger which realize the verifiability of the integrity of medical record.A consensus mechanism based on election of miners is also used in the scheme,which achieves the purpose of improving the efficiency of the consensus mechanism in blockchain network.The security and performance analysis shows that the proposed scheme is more functional and operates efficiently.2.In view of the shortcomings of the existing EMR management system in reducing patient management burden and achieving flexible sharing functions,this paper also proposes an EMR management system that supports hierarchical attribute division.Referring to the common methods on seeking medical treatment in China,the hierarchical attribution structure of EMR are divided according to the division method of hospital departments,which is more suitable for the scenario of medical institutions interconnection.The system combines the hierarchical key distribution scheme and key aggregation cryptosystem to support the dynamic addition of medical records and realize the function of sharing single,multiple or medical records under the entire categories,which provide patients with a convenient EMR management solution.The comparative analysis and simulation experiments indicate that the system reduces the patient’s overhead in key management,and has advantages of security and high efficiency.