MEChain: A Multi-layer Blockchain Structure with Hierarchical Consensus for Secure EHR System
Huan Yu Wu, Lun Jie Li, Hye-Young Paik, Salil S. Kanhere · 2021 IEEE 20th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom) · 2021
Although Electronic Health Record (EHR) systems are widely used in health care organisations, they still face security and privacy problems. Blockchain is considered a promising technology that could help overcome many of these problems. However, efforts to incorporate blockchain into EHR systems so far have shown heavy overhead, unsuitable software architectural structures and inefficient consensus protocols. We present ME Chain, a multi-layer blockchain structure, which aims to solve the adoption, storage and consensus problems when implementing blockchain in EHR systems. The multi-layer structure is better suited for the operational hierarchy in health organisations and is supported by the following novel features: (i) a consensus implementation optimised for the multi-layer operations, which solves the byzantine failure in both layers, hence guarantees consistency, it also reduces request confirmation latency and overhead and provides every layer with the ability to correct the faults, (ii) a data synchronisation method for some nodes that does not receive the correct information or simply get offline to catch up with the system, data verification and retrieve mechanisms to protect data integrity. Experiments are conducted to evaluate ME Chain in terms of security, performance and storage cost. The results show that ME Chain can establish a secure EHR with high performance and acceptable storage cost.