Scaling Byzantine Fault Tolerant (BFT) systems in terms of membership is important for secure applications with large participation such as blockchains. While traditional protocols have low latency, they cannot handle many processors. Conversely, blockchains often have hundreds to thousands of processors to increase robustness, but they typically have high latency or energy costs.

We describe various sources of unscalability in BFT consensus protocols. To improve performance, many BFT protocols optimize the “normal case,” where there are no failures. This can be done in a modular fashion by wrapping existing BFT protocols with a building block that we call alliance. In normal case executions, alliance can scalably determine if the initial conditions of a BFT consensus protocol predetermine the outcome, obviating running the consensus protocol.

We give examples of existing protocols that solve alliance. We show that a solution based on hypercubes and MACs has desirable scalability and performance in normal case executions, with only a modest overhead otherwise. We provide important optimizations. Finally, we evaluate our solution using the ns3 simulator and show that it scales up to thousands of processors and compare with prior work in various network topologies.

根据成员资格扩展拜占庭容错 (BFT) 系统对于具有大量参与的安全应用程序（例如区块链）非常重要。虽然传统协议具有低延迟，但它们无法处理许多处理器。相反，区块链通常有成百上千个处理器来提高鲁棒性，但它们通常具有高延迟或能源成本。

我们描述了 BFT 共识协议中各种不可扩展性的来源。为了提高性能，许多 BFT 协议优化了没有故障的“正常情况”。这可以通过使用我们称为联盟的构建块包装现有的 BFT 协议以模块化方式完成。在正常情况下，联盟可以可扩展地确定 BFT 共识协议的初始条件是否预先确定了结果，从而避免运行共识协议。

我们给出了解决联盟的现有协议的例子。我们展示了一个基于超立方体的解决方案和苹果s 在正常情况下具有理想的可扩展性和性能，否则只有适度的开销。我们提供重要的优化。最后，我们使用 ns3 模拟器评估我们的解决方案，并表明它可以扩展到数千个处理器，并与各种网络拓扑中的先前工作进行比较。