Med-PPPHIS: Blockchain-Based Personal Healthcare Information System for National Physique Monitoring and Scientific Exercise Guiding.

The dissemination of electronic medical data among professional personnel has been perceived to be an important breakthrough for the discovery of new technologies and therapies for curing diseases. However, in the current medical data management, it is difficult to share medical data due to the fragmentation of medical data and the lack of effective sharing methods. On the other hand, the security of medical data is difficult to protect because the centralized data storage is vulnerable to attack and tampering. Therefore, we propose a model called Med-PPPHIS, which consists of a permission-less blockchain and a permissioned blockchain, named Med-DLattice, to serve the management of user's personal health information and form a chained protection mechanism for medical data. Med-DLattice features Directed Acyclic Graph (DAG) structure, where each account updates its Account-DAG asynchronously to other unrelated accounts. The Med-DLattice nodes can reach an efficient consensus with proposed DPoS-Quorum algorithm. Based on this model, by converting the medical data into on-chain tokens, a safe and efficient channel for data circulation is established, while the privacy of data is secured. We implement a prototype of Med-PPPHIS and introduce a blockchain-based closed-loop method for chronic disease management, which initially applies the model to national physique monitoring in Anhui Province, China. The performance of the model is evaluated by simulating 500 nodes on 25 AliCloud ECS virtual machines. Experimental result shows that Med-PPPHIS has low latency and high throughput, and the security analysis shows that the model is able to prevent Sybil attacks, DDoS attacks, etc.