Multimmit：扩展块以实现更快的终结性

中文摘要 AI 辅助

为满足现代区块链系统的吞吐量需求，状态机复制（SMR）协议让多个处理器并行传播交易块，之后通过共识建立全序。认证方法等待仲裁法定证块的可用性，虽稳健但增加消息延迟；未经认证的方法让提案立即引用块，速度快但关键路径上获取引用数据时性能迅速下降。现有最优的Raptr对顺序敏感。本文提出Multimmit协议，适用于\(n \ge 5f + 1\)个处理器，结合了每视图一轮投票的共识层和多链数据传播。投票相对于领导者的提案进行，报告选民对每条链的支持程度，且可证明新块。传播时间为\(t\)的交易块，期望在\(t + 3\delta\)时排序，最快在\(t + 2\delta\)时排序。故障时降级优雅，错误生产者仅延迟自己链的块，其他链最多等待一个视图进行放置。没有领导者能既终结其领导块又排除诚实链的新的、广泛传播的块。共识流量每视图数十千字节，与交易量无关。

英文摘要

To meet the throughput demands of modern blockchain systems, protocols for State Machine Replication (SMR) increasingly have many processors disseminate blocks of transactions in parallel, with consensus then establishing a total ordering on the blocks of all producers. Such designs face a choice as to when a block may enter the ordering. Certified approaches wait for a quorum to attest a block's availability, which is robust but adds message delays to every transaction. Uncertified approaches let proposals reference blocks immediately, which is fast but degrades rapidly when referenced data must be fetched on the critical path. Raptr, the state of the art, takes a middle course, finalising the longest prefix of the leader's proposal that a quorum holds, so that no processor ever blocks or fetches. The remaining weakness is sensitivity to order: if the data behind a single early batch is withheld, the proposal finalises little or nothing, so individual faulty producers can still deny the system its optimistic path. We present Multimmit, a protocol for $n \ge 5f+1$ processors combining a consensus layer requiring one round of voting per view with multi-chain data dissemination. Votes are cast relative to the leader's proposal, reporting per chain how far the voter can support it, and may themselves attest fresh blocks beyond it. A transaction block disseminated at time $t$ is ordered by $t+3δ$ in expectation and $t+2δ$ at best, measured from the block's dissemination rather than the leader's proposal. Degradation under faults is graceful: a faulty producer delays only its own chain's blocks, costing other chains at most a one-view wait for placement. No leader can both finalise its leader block and exclude a fresh, well-circulated block of an honest chain. Consensus traffic is tens of kilobytes per view, independent of transaction volume.

发表机构

• London School of Economics（伦敦政治经济学院）
• Commonware

机构由 AI 辅助整理，请以论文原文为准。