Achieving low-latency consensus in geographically distributed systems remains a key challenge for blockchain and distributed database applications. To this end, there has been significant recent interest in State-Machine-Replication (SMR) protocols that achieve 2-round finality under the assumption that $5f+1\leq n$, where $n$ is the number of processors and $f$ bounds the number of processors that may exhibit Byzantine faults. In these protocols, instructions are organised into views, each led by a different designated leader, and 2-round finality means that a leader's proposal can be finalised after just a single round of voting, meaning two rounds overall (one round for the proposal and one for voting). We introduce Minimmit, a Byzantine-fault-tolerant SMR protocol with lower latency than previous 2-round finality approaches. Our key insight is that view progression and transaction finality can operate on different quorum thresholds without compromising safety or liveness. Experiments simulating a globally distributed network of 50 processors, uniformly assigned across ten virtual regions, show that the approach leads to a 23.1% reduction in view latency and a 10.7% reduction in transaction latency compared to the state-of-the-art.

翻译：在地理分布系统中实现低延迟共识仍然是区块链和分布式数据库应用面临的关键挑战。为此，近期人们对状态机复制协议产生了浓厚兴趣，这些协议在假设 $5f+1\leq n$ 的条件下实现两轮最终性，其中 $n$ 是处理器数量，$f$ 是可能表现出拜占庭故障的处理器数量上限。在这些协议中，指令被组织成视图，每个视图由不同的指定领导者主导，两轮最终性意味着领导者的提案仅需一轮投票即可最终确定，即总共两轮（一轮用于提案，一轮用于投票）。我们提出 Minimmit，一种拜占庭容错的状态机复制协议，其延迟低于先前的两轮最终性方案。我们的核心见解是，视图推进和交易最终性可以在不同的法定人数阈值下运行，而不会影响安全性或活性。模拟由 50 个处理器组成的全球分布式网络（均匀分配在十个虚拟区域中）的实验表明，与现有最先进技术相比，该方法使视图延迟降低了 23.1%，交易延迟降低了 10.7%。