Consensus algorithm for medical data storage and sharing based on master–slave multi-chain of alliance chain

The safe storage and sharing of medical data have promoted the development of the public medical field. At the same time, blockchain technology guarantees the safe storage and sharing of medical data. However, the consensus algorithm in the current medical blockchain cannot meet the requirements of low delay and high throughput in the large-scale network, and the identity of the primary node is exposed and vulnerable to attack. Therefore, this paper proposes an efficient consensus algorithm for medical data storage and sharing based on a master–slave multi-chain of alliance chain (ECA_MDSS). Firstly, institutional nodes in the healthcare alliance chain are clustered according to geographical location and medical system structure to form a multi-zones network. The system adopts master–slave multi-chain architecture to ensure security, and each zone processes transactions in parallel to improve consensus efficiency. Secondly, the aggregation signature is used to improve the practical Byzantine fault-tolerant (PBFT) consensus to reduce the communication interaction of consensus in each zone. Finally, an efficient ring signature is used to ensure the anonymity and privacy of the primary node in each zone and to prevent adaptive attacks. Meanwhile, a trust model is introduced to evaluate the trust degree of the node to reduce the evil done by malicious nodes. The experimental results show that ECA_ MDSS can effectively reduce communication overhead and consensus delay, improve transaction throughput, and enhance system scalability.