Research On Secure Storage And Sharing Of Medical Data Based On Blockchain

Medical data is of great value to doctors’ diagnoses and medical research,but it is related to patients’ privacy.Therefore,how to store and share medical data safely and efficiently is a major difficulty in the medical industry.Traditional medical data is stored in the database of each medical institution,which not only forms data islands and makes it difficult to share data,but also makes data easy to be stolen and tampered with by malicious users.In response to these problems,researchers propose to use the cloud to realize the storage and sharing of medical data.However,cloud servers are vulnerable to targeted attacks,and they may steal data for their own interests,resulting in privacy data leakage.Blockchain technology has the characteristics of decentralization,non-tampering,and traceability,which provide a new solution to the security problems in medical data storage and sharing.This paper studies the problems of low system efficiency,data privacy leakage,and inactive sharing caused by a large number of medical institutions,the increase in data processing,and data indifference access.A medical data storage and sharing model based on blockchain master-slave multi-chain is proposed,and a medical data hierarchical access control mechanism based on blockchain is designed to realize the safe storage and sharing of medical data.The specific research contents of this paper are as follows:1.Aiming at the problems of high node storage pressure and low efficiency of blockchain systems caused by a large scale of medical data,a large number of medical institutions and miscellaneous systems,and frequent data storage and sharing frequent data storage and sharing,this paper proposes a medical data storage and sharing model based on blockchain master-slave multi-chain.Firstly,the medical large-scale data encryption is stored in the Inter Planetary File System(IPFS)to alleviate the node pressure,and the data storage address,symmetric key and other information and subsequent shared records are stored on the alliance chain,and the partition idea is used to build the master-slave multichain to build the alliance chain system so that the institutional partition runs and processes the data.Secondly,in order to improve the consensus efficiency of the system,an efficient consensus algorithm for medical data storage and sharing(ECA＿MDSS)is designed.The nodes in the chain are zoned by a zoning algorithm to construct the master-slave chain operation area,and the aggregate signature is used to reduce the communication interaction in the consensus.The ring signature is used to ensure the anonymity of the master node,and a trust model is established to constrain the node behavior.Finally,security and activity analysis and experimental simulation show that the proposed model is secure and active,symmetric encryption and decryption,IPFS system and trust model meet the requirements,and the improved ECA＿MDSS algorithm has the advantages of high throughput,low latency,and strong scalability.2.Aiming at the problems of inactive sharing of medical data caused by medical data indifference access and the untimely response of institutions when the amount of data access increases in the medical blockchain,this paper proposes a medical data hierarchical access control mechanism based on blockchain.Firstly,the patient’s medical data is graded according to the degree of sensitivity,and the doctor-patient signature is performed using the improved content-extraction signature to complete the signature authorization.Secondly,the institution encrypts and uploads different levels of data subsets with different symmetric keys and formulates different access strategies.Different keys are encrypted using the ciphertext policy attribute base,and then the access strategy and related data are stored in the smart contract.The access transaction triggers the contract to automatically return the data and complete the access to the data.Finally,the security analysis shows that the proposed access mechanism is secure and the improved system model is secure.The scheme evaluation and experimental analysis prove that the improved interception signature is efficient and feasible.