Byzantine Consensus is fundamental for building consistent and fault-tolerant distributed systems. In traditional quorum-based consensus protocols, quorums are defined using globally known assumptions shared among all participants. Motivated by decentralized applications on open networks, the Stellar blockchain relaxes these global assumptions by allowing each participant to define its quorums using local information. A similar model called Consensus with Unknown Participants (CUP) studies the minimal knowledge required to solve consensus in ad-hoc networks where each participant knows only a subset of other participants of the system. We prove that Stellar cannot solve consensus using the initial knowledge provided to participants in the CUP model, even though CUP can. We propose an oracle called sink detector that augments this knowledge, enabling Stellar participants to solve consensus.

翻译：拜占庭共识是构建一致且容错的分布式系统的基础。在传统的基于法定人数的共识协议中，法定人数是利用所有参与者共享的全局已知假设来定义的。受开放网络上去中心化应用的驱动，恒星区块链通过允许每个参与者利用局部信息定义其法定人数，放宽了这些全局假设。一种称为“未知参与者共识”（CUP）的类似模型研究了在自组织网络中解决共识所需的最少知识，其中每个参与者只知道系统中其他参与者的一个子集。我们证明，即便CUP模型能够解决共识，但恒星无法利用CUP模型中提供给参与者的初始知识来解决共识。我们提出了一种名为“汇检测器”的神谕，该神谕增强了这种知识，使得恒星参与者能够解决共识。