Simple-IT：实用的低延迟无签名BFT共识
Simple-IT: Practical Low-Latency Signature-Free BFT Consensus
Qianyu Yu, Juan Villacis, Giuliano Losa, Zhuolun Xiang, Xuechao Wang
AI 速览：提出一种基于领导者的无签名拜占庭容错共识协议Simple-IT，作者报告其理论延迟为4个消息延迟、乐观路径为3个，并在跨地域测试床上取得与量子脆弱型先进协议相当的吞吐与延迟。
Recent advances in quantum computing pose a looming threat to most current Byzantine fault-tolerant (BFT) consensus protocols, which rely on quantum-vulnerable public-key signature schemes such as Ed25519 and BLS12-381. Instead of switching to much more expensive post-quantum secure signature schemes, an alternative is to use signature-free protocols, which rely only on cheap, post-quantum secure authenticated channels. In this paper, we ask whether signature-free BFT consensus protocols can match the performance of current state-of-the-art, quantum-vulnerable BFT consensus protocols. While previous work on the Sailfish++ protocol showed that state-of-the-art throughput is attainable signature-free, the question of latency is still open. Several recent signature-free protocols have low latency in theory, but they are all very intricate, and no practical implementation has so far been presented. In this work, we propose Simple-IT, a new leader-based, signature-free BFT consensus protocol that achieves a theoretical latency of 4 message delays (one more than the optimum), and only 3 on its optimistic path. Crucially, Simple-IT is simple enough to be amenable to implementation and to practical optimizations such as speculative pipelining, and, as we show experimentally in a geo-distributed testbed, it achieves both throughput and latency competitive with state-of-the-art quantum-vulnerable protocols.