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：在地理分布式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，该协议在假设$5f+1\leq n$（其中$n$为处理器总数，$f$为可能发生拜占庭故障的处理器数量上限）的条件下实现两轮最终性。在这类协议中，指令被组织成多个视图，每个视图由不同的指定领导者主导，而两轮最终性意味着领导者的提案仅需经过一轮投票即可完成最终确认，即总共两轮（一轮用于提案提交，一轮用于投票表决）。本文提出Minimmit，这是一种拜占庭容错的状态机复制协议，其延迟低于现有的两轮最终性方案。我们的核心洞见在于：视图切换与交易最终性可以在不同法定人数阈值下运行，同时保证安全性与活性不受影响。在模拟由50个处理器组成的全球分布式网络（均匀分配于十个虚拟区域）的实验中，该方法相较于最先进方案，视图延迟降低23.1%，交易延迟降低10.7%。