ChonkyBFT: Consensus Protocol of ZKsync

Bruno França; Denis Kolegov; Igor Konnov; Grzegorz Prusak

ChonkyBFT: Consensus Protocol of ZKsync

Distributed, Parallel, and Cluster Computing 2025-03-20 v1 Cryptography and Security Logic in Computer Science

Authors: Bruno França , Denis Kolegov , Igor Konnov , Grzegorz Prusak

Abstract

We present ChonkyBFT, a partially-synchronous Byzantine fault-tolerant (BFT) consensus protocol used in the ZKsync system. The proposed protocol is a hybrid protocol inspired by FAB Paxos, Fast-HotStuff, and HotStuff-2. It is a committee-based protocol with only one round of voting, single slot finality, quadratic communication, and n >= 5f + 1 fault tolerance. This design enables its effective application within the context of the ZKsync rollup, achieving its most critical goals: simplicity, low transaction latency, and reduced system complexity. The target audience for this paper is the ZKsync community and others worldwide who seek assurance in the safety and security of the ZKsync protocols. The described consensus protocol has been implemented, analyzed, and tested using formal methods.

Keywords

byzantine fault tolerance

Cite

@article{arxiv.2503.15380,
  title  = {ChonkyBFT: Consensus Protocol of ZKsync},
  author = {Bruno França and Denis Kolegov and Igor Konnov and Grzegorz Prusak},
  journal= {arXiv preprint arXiv:2503.15380},
  year   = {2025}
}

ChonkyBFT: Consensus Protocol of ZKsync

Abstract

Keywords

Cite

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