Optimal Good-Case Latency for Rotating Leader Synchronous BFT

Authors Ittai Abraham, Kartik Nayak, Nibesh Shrestha

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Author Details

Ittai Abraham
  • VMware Research, Herzliya, Israel
Kartik Nayak
  • Duke University, Durham, NC, USA
Nibesh Shrestha
  • Rochester Institute of Technology, NY, USA

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Ittai Abraham, Kartik Nayak, and Nibesh Shrestha. Optimal Good-Case Latency for Rotating Leader Synchronous BFT. In 25th International Conference on Principles of Distributed Systems (OPODIS 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 217, pp. 27:1-27:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


This paper explores the good-case latency of synchronous Byzantine Fault Tolerant (BFT) consensus protocols in the rotating leader setting. We first present a lower bound that relates the latency of a broadcast when the sender is honest and the latency of switching to the next sender. We then present a matching upper bound with a latency of 2Δ (Δ is the pessimistic synchronous delay) with an optimistically responsive change to the next sender. The results imply that both our lower and upper bounds are tight. We implement and evaluate our protocol and show that our protocol obtains similar latency compared to state-of-the-art stable-leader protocol Sync HotStuff while allowing optimistically responsive leader rotation.

Subject Classification

ACM Subject Classification
  • Security and privacy → Distributed systems security
  • Distributed Computing
  • Byzantine Fault Tolerance
  • Synchrony


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