Fast TetraBFT: Optimizing Latency Where It Matters
2026-06-02 • Distributed, Parallel, and Cluster Computing
Distributed, Parallel, and Cluster Computing
AI summaryⓘ
The authors study a type of consensus protocol called unauthenticated Byzantine consensus, which is useful for blockchains without strict trust assumptions. They focus on reducing the time it takes for all good participants to agree in ideal conditions. While a previous protocol (ForgetIT) achieved this quickly but was complex, the authors created Fast TetraBFT, which is simpler and matches the fastest decision time using fewer messages. Their approach improves an existing protocol while keeping communication efficient and memory usage low.
Byzantine consensusunauthenticated channelspartial synchronygood-case latencymessage delaysTetraBFTFault toleranceblockchain consensuscommunication complexity
Authors
Antonio J. Fernández-Pinto, Manuel Bravo, Gregory Chockler, Alexey Gotsman
Abstract
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.