标题： 通用可组合的Tendermint终止分析 显示英文标题

标题： Universally Composable Termination Analysis of Tendermint

摘要： 现代在对抗性环境中运行的区块链系统需要强大的共识协议，这些协议在存在网络延迟攻击时能够保证安全性和终止性。Tendermint 是一种在联盟链中广泛采用的共识协议，它实现了高吞吐量和最终性。然而，之前对安全性和终止性的分析是独立进行的，没有考虑与其他在并发方式下与其交互的协议的组合。此外，由拜占庭对手引起的自适应网络延迟下的终止属性尚未被正式分析。本文首次对 Tendermint 进行了通用可组合（UC）安全分析，证明了其对策略性消息延迟攻击的弹性。通过构建 Tendermint 的 UC 理想模型，我们形式化了其核心机制：基于阶段的共识过程、动态超时、提议锁定、领导者轮换以及其他机制，在一个选择性延迟协议消息的网络对手下。我们的主要结果证明了 Tendermint 协议 UC 实现了理想 Tendermint 模型，这确保了有限的终止延迟，即在最多$f<n/3$个节点是拜占庭的情况下（其中$n$是参与共识的节点数量），只要在网络部分同步假设下网络延迟保持在协议定义的阈值内，就能保证终止。具体来说，通过 UC 框架内的形式化证明，我们展示了 Tendermint 保持安全性和终止性。根据 UC 的组合定理，这保证了当 Tendermint 与各种区块链组件组合时，这些属性得以保持。 显示英文摘要

摘要： Modern blockchain systems operating in adversarial environments require robust consensus protocols that guarantee both safety and termination under network delay attacks. Tendermint, a widely adopted consensus protocol in consortium blockchains, achieves high throughput and finality. However, previous analysis of the safety and termination has been done in a standalone fashion, with no consideration of the composition with other protocols interacting with it in a concurrent manner. Moreover, the termination properties under adaptive network delays caused by Byzantine adversaries have not been formally analyzed. This paper presents the first universally composable (UC) security analysis of Tendermint, demonstrating its resilience against strategic message-delay attacks. By constructing a UC ideal model of Tendermint, we formalize its core mechanisms: phase-base consensus procedure, dynamic timeouts, proposal locking, leader rotation, and others, under a network adversary that selectively delays protocol messages. Our main result proves that the Tendermint protocol UC-realizes the ideal Tendermint model, which ensures bounded termination latency, i.e., guaranteed termination, even when up to $f<n/3$ nodes are Byzantine (where $n$ is the number of nodes participating in the consensus), provided that network delays remain within a protocol-defined threshold under the partially synchronous net assumption. Specifically, through formal proofs within the UC framework, we show that Tendermint maintains safety and termination. By the composition theorem of UC, this guarantees that these properties are maintained when Tendermint is composed with various blockchain components.