Research Of Medical Data Security Sharing Model Based On Blockchain

With the rapid development of information technology,the medical field is also accelerating the construction of medical informatization,the essence of which is to realize the sharing of medical data.Medical data accurately records the detailed information of patients,and the sharing of medical data is beneficial to both the individual condition and the information construction of the country.At present,there are still some problems in the realization of medical data sharing: the data is stored centrally in the database of the hospital where the patients are treated,which prevents the data sharing and makes it easy to be stolen and tampered by illegal users.To solve these problems,many medical institutions use cloud servers for data storage and sharing,which realizes data sharing to a certain extent.However,there is a risk that the cloud server will be attacked,or the cloud service providers resell data for the benefit,which will lead to a series of problems such as the privacy leakage of patients.Blockchain is a distributed ledger technology,which is decentralized,tamper proof and traceable.Using these advantages can effectively solve the problem of medical data being tampered or leaked.Therefore,this paper studies the secure storage and efficient sharing of medical data based on blockchain technology.1.Aiming at the problems of data sharing difficulty and data privacy leakage among medical institutions,a secure medical data sharing scheme based on consortium blockchain is proposed.In this scheme,cloud memory is used to store medical data ciphertext,and the consortium blockchain is used to store relevant metadata mode,so as to realize the safe storage and sharing of data.In addition,the scheme also designs a medical data security sharing protocol,which combines intelligent contract and ciphertext policy attribute based encryption technology.It can not only achieve fine-grained access control of data,but also restrict the access of data users from the time dimension.The security analysis shows that the scheme can safely store and share medical data,and the comparative analysis and simulation experiments show that the scheme can achieve fine-grained access control with time dimension.2.In view of the safety and efficiency of the consensus mechanism used in the medical consortium blockchain,a consensus mechanism scheme applicable to the medical consortium blockchain is proposed.Based on the practical Byzantine fault tolerant algorithm,this scheme introduces a credit mechanism to monitor the consensus behavior of nodes,selects nodes by resource contribution,and uses a node conversion mechanism to eliminate Byzantine nodes.The experimental results show that the consensus nodes selected by this scheme are more reliable,which can reduce the use of communication resources and improve the efficiency of the system in the long run.