Research On Privacy Protection Scheme Of Medical Data Based On Blockchain

The development of information technology has driven the rapid development of digital medical care.It integrates computer information related technologies into the medical process.As a novel and highly modern information medical method,digital medical care has changed the storage and sharing of medical data and greatly promoted the development of medical care.In the process of implementing information construction in the medical system,if important sensitive medical data are directly placed on the cloud server,some important data are likely to be leaked when the server is attacked by criminals.This leads to a series of chain problems such as illegal sale of private information.Block chain technology has the advantages of distributed sharing of global books,openness and transparency,decentralized community,etc.It can well solve the problem of data privacy and security.The application of block chain technology in digital medicine is helpful to promote the privacy protection of medical data.This paper constructs a medical system based on block chain.The system is built on the alliance chain.By improving the practical Byzantine fault-tolerant algorithm,it ensures the safe and stable operation of the system with little computing power.By combining group signature and asymmetric encryption algorithm on fabric,the security of patient medical data is guaranteed.The main research work is as follows:This paper studies the block chain technology based on PBFT,and proposes a PBFT consensus mechanism based on confidence vote classification,namely CPBFT(Credit Practical Byzantine Fault Tolerance).Aiming at the problem of large consensus delay caused by random selection of nodes in consensus mechanism,the reliability of nodes is evaluated by node division mechanism,and nodes with high reputation value are dynamically selected to participate in consensus,thus reducing the probability of malicious nodes becoming consensus nodes.Aiming at the problem of low consensus efficiency when there are many nodes,two methods,reputation reward and punishment and reputation election,are used to quickly eliminate abnormal nodes.Compared with PBFT scheme,the experimental results show that in the long-term operation of the system,this scheme can reduce Byzantine nodes and communication overhead in the consensus process,and improve fault tolerance and throughput.A medical data privacy protection model based on Hyperledger Fabric is proposed.In the process of studying the super book Fabric transaction,the proposal is sent to the endorsement node and the sorting node stage for optimization and encryption;Secondly,according to the characteristics of super book Fabric,the existing group signature algorithm is upgraded by using homomorphic encryption group signature method.Asymmetric encryption algorithm and upgraded group signature algorithm are used to optimize the transaction process,hide the proposal data information and enhance the security of transaction information.In addition,when there is a dispute over the group signature,the identity information of the signer can be detected by the group administrator opening the group to meet the regulatory requirements.