A Design of Electronic Medical Record System based on Permissioned Blockchain

Abstract

Blockchain, due to its decentralized, verifiable, and security features, is increasingly used in more and more scenarios, but the original public chain cannot meet the needs of some enterprise or group financial scenarios or medical scenarios, and these more segmented special application scenarios have added many requirements for security, identity and role definition to the blockchain system, so people have launched a lot of research on permissioned blockchain. However, the Practical Byzantine Fault-Tolerant (PBFT) based permissioned chain is no longer able to meet the increasing demand of nodes in today's healthcare system due to the shortcomings such as high communication volume and poor scalability. In this thesis, we will explore the application of permissioned blockchain in medical scenario, and try to optimize the communication volume of PBFT by cascading network, optimize its communication complexity from O(n^2) to O(n), and add credit mechanism to reduce the probability of key nodes becoming Byzantine nodes. We also add a series of scalability mechanisms and new node verification addition and removal mechanisms to compensate for the disadvantage of non-dynamic number of nodes in the original PBFT.