Research And Implementation Of Electronic Medical Record Privacy Protection And Sharing System Based On Blockchain

As a new carrier of patient medical information in the era of Internet development,electronic medical records（EMR）store the patient’s previous medical condition data,provide convenient data storage services,and allow doctors to focus on the diagnosis and treatment of patients.Through the sharing of EMR data,doctors are able to judge the patient’s condition more quickly,comprehensively and accurately,so as to provide more efficient treatment plans.However,the current data mobility between different hospitals is poor,and the patient’s EMR data cannot be shared across hospitals in a timely manner,which brings inconvenience to patients.In addition,the current medical system usually adopts centralized storage for the patient’s EMR data.If the storage system is attacked,the patient is at risk of private data leakage and EMR data being tampered with.Based on the above problems,this paper firstly conducts in-depth research on the consensus process of the electronic medical record sharing system based on blockchain,constructs a consensus environment based on alliance,and improves the existing Practical Byzantine Fault Tolerance（PBFT）algorithm,which reduces the probability of the master node acting maliciously,improves the operating efficiency of the algorithm,and makes it more suitable for electronic medical record sharing scenarios.Secondly,in view of the problem that the transaction data involved in the use of blockchain for data sharing can be traced,a scheme for anonymous processing of transaction records is designed in combination with ring signatures,which delinks the direct connection between patients and hospitals in transaction records.As a consequence,patient privacy is protected.Finally,based on the above research,a system for sharing medical record data based on blockchain that can protect patient privacy is designed and implemented.Using the form of "on-chain" and "off-chain" separate storage mechanisms,the EMR data is encrypted and stored in the Inter Planetary File System（IPFS）.Subsequently,the IPFS address is recorded in a blockchain transaction.Under the condition that the EMR data is not tampered with and the patient’s privacy is not leaked,the decentralized storage of transaction data is realized.Upon a Patient’s visit to a hospital,he only needs to query the transaction data according to the blockchain transaction address,and the data of his own EMR can be decrypted and provided to the doctor,thus realizing the efficient sharing of the electronic medical record across hospitals.The experimental test shows that the EMR privacy protection sharing system based on blockchain constructed in this paper can effectively realize the safe and efficient sharing of EMR data,and achieves the expected goals and requirements of designing this system.