Research On Blockchain Medical Privacy Data Sharing Based On Ring Signatur

With the development of medical informatization,medical data sharing is of great significance for promoting medical diagnosis,reducing disputes between doctors and patients and improving scientific research ability.Normative storage is the premise of sharing operation.The large-scale growing demand for sharing challenges the reliable storage of medical data.At the same time,the high sensitivity of medical data and the malicious sharing between institutions are easy to make the privacy of data and sharers leaked.The sharers mainly exist among patients,hospitals and scientific research institutions.How to protect the identity information of individuals and entities while ensuring the safe sharing of private data is worthy of in-depth exploration.Blockchain,as a trusted platform and related cryptography technologies,provides solutions to the above problems.Therefore,facing the development trend of intelligent medical care,this thesis studies the realization of unconditional anonymity on the chain and the security sharing of private data,based on blockchain technology and the advantages of ring signature algorithm.In view of the above requirements,the main research work includes two parts,as follows:(1)Aiming at the problem of patients’ weak authority in electronic medical images system,considering patients’ own interests,a privacy sharing scheme of electronic medical images based on dual-ring signature is proposed.Medical images,as special data,are the key to disease diagnosis.Firstly,in the data encryption stage,the ring signature is combined with the two-party signature,and the identity of patients and doctors is hidden by using the dual-ring signature algorithm to realize anonymous sharing.Then,in the data storage stage,the encrypted image is reliably saved by using blockchain and distributed storage system to prevent image information from being tampered with.Finally,in the data sharing stage,smart contracts are deployed to authenticate transactions and reward mechanisms are set up.The interaction between patients and medical research institutions can realize the safe sharing of patient-centered image data.Through security analysis and experiments,the advantages of this scheme compared with most existing schemes are demonstrated.In terms of security,it has higher anonymity,unforgeability and non-repudiation,which meets the requirements of protecting user identity and secure sharing.In addition,smart contract functions are designed to evaluate the rationality and feasibility of the shared reward mechanism from the aspects of development cost and response delay.(2)Aiming at the special requirements in the application scenario of medical institutions,an anonymous and efficient sharing scheme based on dynamic configuration of medical diagnosis chain(MDChain)is proposed to speed up the sharing process of diagnostic records.The scheme realizes data exchange among entities(medical equipment,hospitals and scientific research institutions).It also solves the problem of isolated island of medical data.First of all,set up a trusted management organization,which is responsible for the joining of members in the MDChain and the management and maintenance of the chain.On the one hand,on the basis of ring signature,stealth addresses and access tokens are introduced to perform anonymous operations between shared entities.After the management organization verifies that it is legal,it completes the sharing operation.On the other hand,according to the urgency of data,multi-channel MDChain is used to allocate the priority of medical data.An effective node optimization algorithm is designed to dynamically configure the block transactions and verify the quantitative relationship between nodes in MDChain.The algorithm improves the transaction processing speed and realizes efficient anonymous sharing between entities.The security analysis and performance evaluation show that the scheme meets the requirements of medical data sharing.This method solves the problem of identity disclosure in the process of sharing,and improves privacy and sharing rate.