Abstract: According to the status quo of medical informationization in China,the traditional electronic data model has the following problems in information storage.Firstly,electronic data have poor standardization and slow circulation.Secondly,electronic data security and privacy are threatened.Aiming at the security problem of information storage and the sharing of information between medical information systems,combined with the consensus mechanism of blockchain,encryption mechanism and peer-to-peer network,a blockchain-based information management scheme was proposed to realize the storage and sharing of medical information,which is non-tamperable and decentralized.The consensus of the network nodes is realized through the improved Byzantine protocol,the medical information is shared through the access control mechanism,the public information of the medical information is saved through the blockchain,and the real data of the medical treatment is encrypted and stored in the database or the cloud,which conveniently and effectively implements the storage of sensitive medical data and the sharing of information between systems.In the environment of the alliance chain,several network nodes are selected for security and performance testing.The experimental analysis shows that the proposed scheme has better performance in terms of security protection such as tamper resistance,privacy protection and throughput.In addition,the indexing mechanism proposed in this scheme can achieve fast retrieval and improve retrieval efficiency.By establishing a test network,the feasibility of this program in medical information storage is proved.The decentralized and non-tamperable management of the program using the blockchain can greatly improve the efficiency and the quality of medical services.It lays a good foundation for further research on the bottom technology of block chain and for exploring the application of block chain technology in the field of medical information.

Key words: Consensus mechanism, Information security, Information sharing, Medical blockchain