College of Information Science and Engineering, Xinjiang University, Ürümqi, 830046, China.
Sci Rep. 2023 Jan 2;13(1):20. doi: 10.1038/s41598-022-27228-1.
The consensus algorithm is very critical in any blockchain system, because it directly affects the performance and security of the blockchain system. At present, the classic Practical Byzantine Fault Tolerance Algorithm (PBFT), which is mainly used in the consortium chain, will lead to system communication congestion and reduced throughput when the number of nodes increases, so the PBFT algorithm is not suitable for large-scale consortium chains. In response to the above problems, this paper proposes a new clustering-based sharding consensus algorithm (KBFT), which aims to ensure that the consortium chain takes into account decentralization, security and scalability. The KBFT algorithm first uses the K-prototype clustering algorithm to shard the nodes in the network according to mixed attributes, and second, disjoint transactions are used to reach consensus in parallel in different shards. Concurrently, the KBFT algorithm introduces a supervision mechanism and a node credit mechanism, which is used to supervise and score the behavior of the nodes and select the proxy nodes, which improves security. We discuss the choice of shard size with the help of the binomial probability distribution and analyze the probability that the system can successfully form a global block under different node failure probabilities. Finally, the proposed algorithm is evaluated through theoretical analysis and simulation experiments. Results show that the proposed algorithm achieves a marked improvement in scalability and throughput along with a marked reduction in communication complexity compared with the classic baseline algorithm PBFT in this field of study, which improves the operating efficiency of the system and simultaneously guarantees the security and robustness of the system.
共识算法在任何区块链系统中都非常关键，因为它直接影响区块链系统的性能和安全性。目前，主要用于联盟链的经典实用拜占庭容错算法（PBFT）会随着节点数量的增加而导致系统通信拥塞和吞吐量降低，因此 PBFT 算法不适合大规模的联盟链。针对上述问题，本文提出了一种新的基于聚类的分片共识算法（KBFT），旨在确保联盟链兼顾去中心化、安全性和可扩展性。KBFT 算法首先使用 K-原型聚类算法根据混合属性对网络中的节点进行分片，其次，在不同的分片内使用不相交的事务并行达成共识。同时，KBFT 算法引入了监督机制和节点信用机制，用于监督和评分节点的行为，并选择代理节点，从而提高了安全性。我们借助二项式概率分布讨论了分片大小的选择，并分析了在不同节点失效概率下系统成功形成全局块的概率。最后，通过理论分析和仿真实验对所提出的算法进行了评估。结果表明，与该领域的经典基准算法 PBFT 相比，所提出的算法在可扩展性和吞吐量方面有显著提高，同时通信复杂度也显著降低，提高了系统的运行效率，同时保证了系统的安全性和鲁棒性。
