Unauthenticated Byzantine consensus protocols achieve optimal failure resilience while relying only on authenticated point-to-point channels, not authenticated messages. They are an attractive building block for blockchains that do not mandate symmetric trust assumptions as well as for future post-quantum settings. We consider unauthenticated Byzantine consensus in partially synchronous networks and focus on optimizing its good-case latency - the worst-case time for correct processes to reach a decision under favorable conditions. A recently proposed ForgetIT protocol achieves an optimal good-case latency of 3 message delays but employs a highly complex design. We show that this complexity is unnecessary. To this end, we present Fast TetraBFT - an unauthenticated Byzantine consensus protocol that achieves optimal good-case latency by augmenting an existing TetraBFT protocol with a simple fast-path wrapper. Our solution lowers the good-case latency of TetraBFT from 5 to 3 message delays while preserving its bounded space requirements and low communication complexity.

翻译：未认证拜占庭共识协议在仅依赖认证点对点信道而非认证消息的情况下，实现了最优容错性。这类协议对于不强制对称信任假设的区块链以及未来后量子场景而言，是一种极具吸引力的基础构件。我们考虑部分同步网络中的未认证拜占庭共识，并着重优化其良例延迟——即在有利条件下正确进程达成决策的最坏情况时间。近期提出的ForgetIT协议虽实现了3个消息延迟的最优良例延迟，但其设计高度复杂。我们证明这种复杂性并非必要。为此，我们提出Fast TetraBFT——一种通过为现有TetraBFT协议添加简单快速路径封装器来实现最优良例延迟的未认证拜占庭共识协议。我们的解决方案将TetraBFT的良例延迟从5个消息延迟降至3个，同时保留了其有界空间需求与低通信复杂度的特性。