Quorum Systems in Permissionless Networks

Authors Christian Cachin , Giuliano Losa , Luca Zanolini

Thumbnail PDF


  • Filesize: 0.81 MB
  • 22 pages

Document Identifiers

Author Details

Christian Cachin
  • University of Bern, Switzerland
Giuliano Losa
  • Stellar Development Foundation, San Francisco, CA, USA
Luca Zanolini
  • University of Bern, Switzerland


The authors thank anonymous reviewers for helpful feedback.

Cite AsGet BibTex

Christian Cachin, Giuliano Losa, and Luca Zanolini. Quorum Systems in Permissionless Networks. In 26th International Conference on Principles of Distributed Systems (OPODIS 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 253, pp. 17:1-17:22, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


Fail-prone systems, and their quorum systems, are useful tools for the design of distributed algorithms. However, fail-prone systems as studied so far require every process to know the full system membership in order to guarantee safety through globally intersecting quorums. Thus, they are of little help in an open, permissionless setting, where such knowledge may not be available. We propose to generalize the theory of fail-prone systems to make it applicable to permissionless systems. We do so by enabling processes not only to make assumptions about failures, but also to make assumptions about the assumptions of other processes. Thus, by transitivity, processes that do not even know of any common process may nevertheless have intersecting quorums and solve, for example, reliable broadcast. Our model generalizes existing models such as the classic fail-prone system model [Malkhi and Reiter, 1998] and the asymmetric fail-prone system model [Cachin and Tackmann, OPODIS 2019]. Moreover, it gives a characterization with standard formalism of the model used by the Stellar blockchain.

Subject Classification

ACM Subject Classification
  • Theory of computation → Cryptographic protocols
  • Software and its engineering → Distributed systems organizing principles
  • Permissionless systems
  • fail-prone system
  • quorum system


  • Access Statistics
  • Total Accesses (updated on a weekly basis)
    PDF Downloads


  1. Ignacio Amores-Sesar, Christian Cachin, and Jovana Micic. Security analysis of ripple consensus. In OPODIS, volume 184 of LIPIcs, pages 10:1-10:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2020. Google Scholar
  2. Gabriel Bracha. Asynchronous byzantine agreement protocols. Inf. Comput., 75(2):130-143, 1987. Google Scholar
  3. Christian Cachin, Rachid Guerraoui, and Luís E. T. Rodrigues. Introduction to Reliable and Secure Distributed Programming (2. ed.). Springer, 2011. Google Scholar
  4. Christian Cachin, Giuliano Losa, and Luca Zanolini. Quorum systems in permissionless network, 2022. URL: https://doi.org/10.48550/arXiv.2211.05630.
  5. Christian Cachin and Björn Tackmann. Asymmetric distributed trust. In OPODIS, volume 153 of LIPIcs, pages 7:1-7:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2019. Google Scholar
  6. Christian Cachin and Luca Zanolini. Asymmetric asynchronous byzantine consensus. In DPM/CBT@ESORICS, volume 13140 of Lecture Notes in Computer Science, pages 192-207. Springer, 2021. Google Scholar
  7. Miguel Castro and Barbara Liskov. Practical byzantine fault tolerance and proactive recovery. ACM Trans. Comput. Syst., 20(4):398-461, 2002. Google Scholar
  8. Ivan Damgård, Yvo Desmedt, Matthias Fitzi, and Jesper Buus Nielsen. Secure protocols with asymmetric trust. In ASIACRYPT, volume 4833 of Lecture Notes in Computer Science, pages 357-375. Springer, 2007. Google Scholar
  9. Álvaro García-Pérez and Alexey Gotsman. Federated byzantine quorum systems. In OPODIS, volume 125 of LIPIcs, pages 17:1-17:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2018. Google Scholar
  10. Martin Hirt and Ueli M. Maurer. Player simulation and general adversary structures in perfect multiparty computation. J. Cryptol., 13(1):31-60, 2000. Google Scholar
  11. Flavio Paiva Junqueira and Keith Marzullo. Synchronous consensus for dependent process failure. In ICDCS, pages 274-283. IEEE Computer Society, 2003. Google Scholar
  12. Giuliano Losa, Eli Gafni, and David Mazières. Stellar consensus by instantiation. In DISC, volume 146 of LIPIcs, pages 27:1-27:15. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2019. Google Scholar
  13. Dahlia Malkhi, Kartik Nayak, and Ling Ren. Flexible byzantine fault tolerance. In CCS, pages 1041-1053. ACM, 2019. Google Scholar
  14. Dahlia Malkhi and Michael K. Reiter. Byzantine quorum systems. Distributed Comput., 11(4):203-213, 1998. Google Scholar
  15. Dahlia Malkhi, Michael K. Reiter, and Avishai Wool. The load and availability of byzantine quorum systems. SIAM J. Comput., 29(6):1889-1906, 2000. Google Scholar
  16. David Mazières. The Stellar consensus protocol: A federated model for Internet-level consensus. Stellar, available online, https://www.stellar.org/papers/stellar-consensus-protocol.pdf, 2016.
  17. Rafael Pass and Elaine Shi. Hybrid consensus: Efficient consensus in the permissionless model. In DISC, volume 91 of LIPIcs, pages 39:1-39:16. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2017. Google Scholar
  18. Isaac C. Sheff, Robbert van Renesse, and Andrew C. Myers. Distributed protocols and heterogeneous trust: Technical report. CoRR, abs/1412.3136, 2014. URL: http://arxiv.org/abs/1412.3136.
  19. Isaac C. Sheff, Xinwen Wang, Robbert van Renesse, and Andrew C. Myers. Heterogeneous paxos. In OPODIS, volume 184 of LIPIcs, pages 5:1-5:17. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2020. Google Scholar
  20. T. K. Srikanth and Sam Toueg. Simulating authenticated broadcasts to derive simple fault-tolerant algorithms. Distributed Comput., 2(2):80-94, 1987. Google Scholar
Questions / Remarks / Feedback

Feedback for Dagstuhl Publishing

Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail