Sync HotStuff: Simple and practical synchronous state machine replication

Ittai Abraham, Dahlia Malkhi, Kartik Nayak, Ling Ren, Maofan Yin

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Synchronous solutions for Byzantine Fault Tolerance (BFT) can tolerate up to minority faults. In this work, we present Sync HotStuff, a surprisingly simple and intuitive synchronous BFT solution that achieves consensus with a latency of 2? in the steady state (where ? is a synchronous message delay upper bound). In addition, Sync HotStuff ensures safety in a weaker synchronous model in which the synchrony assumption does not have to hold for all replicas all the time. Moreover, Sync HotStuff has optimistic responsiveness, i.e., it advances at network speed when less than one-quarter of the replicas are not responding. Borrowing from practical partially synchronous BFT solutions, Sync HotStuff has a two-phase leader-based structure, and has been fully prototyped under the standard synchrony assumption. When tolerating a single fault, Sync HotStuff achieves a throughput of over 280 Kops/sec under typical network performance, which is comparable to the best known partially synchronous solution.

Original languageEnglish (US)
Title of host publicationProceedings - 2020 IEEE Symposium on Security and Privacy, SP 2020
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages13
ISBN (Electronic)9781728134970
StatePublished - May 2020
Event41st IEEE Symposium on Security and Privacy, SP 2020 - San Francisco, United States
Duration: May 18 2020May 21 2020

Publication series

NameProceedings - IEEE Symposium on Security and Privacy
ISSN (Print)1081-6011


Conference41st IEEE Symposium on Security and Privacy, SP 2020
Country/TerritoryUnited States
CitySan Francisco

ASJC Scopus subject areas

  • Safety, Risk, Reliability and Quality
  • Software
  • Computer Networks and Communications


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