Paper 2025/1856
Optimal Good-Case Latency for Sleepy Consensus
, Columbia University, a16z Crypto Research, University of Illinois at Urbana-Champaign, a16z Crypto ResearchAbstract
In the context of Byzantine consensus problems such as Byzantine broadcast (BB) and Byzantine agreement (BA), the good-case setting aims to study the minimal possible latency of a BB or BA protocol under certain favorable conditions, namely the designated leader being correct (for BB), or all parties having the same input value (for BA). We provide a full characterization of the feasibility and impossibility of good-case latency, for both BA and BB, in the synchronous sleepy model. Surprisingly to us, we find irrational resilience thresholds emerging: 2-round good-case BB is possible if and only if at all times, at least $\frac{1}{\varphi} \approx 0.618$ fraction of the active parties are correct, where $\varphi = \frac{1+\sqrt{5}}{2} \approx 1.618$ is the golden ratio; 1-round good-case BA is possible if and only if at least $\frac{1}{\sqrt{2}} \approx 0.707$ fraction of the active parties are correct.
Metadata
- Available format(s)
-
PDF
- Publication info
- Preprint.
- Contact author(s)
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ye2210 @ columbia edu
jneu @ a16z com
renling @ illinois edu
ntas @ a16z com - History
- 2025-10-08: approved
- 2025-10-07: received
- See all versions
- Short URL
- https://ia.cr/2025/1856
- License
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CC BY-NC-ND
BibTeX
@misc{cryptoeprint:2025/1856,
author = {Yuval Efron and Joachim Neu and Ling Ren and Ertem Nusret Tas},
title = {Optimal Good-Case Latency for Sleepy Consensus},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/1856},
year = {2025},
url = {https://eprint.iacr.org/2025/1856}
}
