Skip to main content

Everyone Knows that Everyone Knows

  • Chapter
  • First Online:
Mathematics, Logic, and their Philosophies

Part of the book series: Logic, Epistemology, and the Unity of Science ((LEUS,volume 49))

Abstract

A gossip protocol is a procedure for sharing secrets in a network. The basic action in a gossip protocol is a telephone call wherein the caller and the callee exchange all the secrets they know. An agent who knows all secrets is an expert. The usual termination condition is that all agents are experts. Instead, we explore some protocols wherein the termination condition is that all agents know that all agents are experts. We call such agents super experts. Additionally, we model that agents who already know that all agents are experts, do not make and do not answer calls. We also model that such protocols are common knowledge among the agents. We investigate conditions under which such gossip protocols terminate, both in the synchronous case, where there is a global clock, and in the asynchronous case, where there is not. We show that a protocol with missed calls can terminate faster than the same protocol without missed calls.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 99.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 129.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 129.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    This is well-defined, see van Ditmarsch et al. (2019) for a justification of a similar semantics.

  2. 2.

    This is also well-defined, see again (van Ditmarsch et al. 2019) for a justification of a similar semantics.

References

  • Apt, K. R., Grossi, D., & van der Hoek, W. (2015). Epistemic protocols for distributed gossiping. In Proceedings of 15th TARK.

    Google Scholar 

  • Apt, K. R., Grossi, D., & van der Hoek, W. (2018). When are two gossips the same? In G. Barthe, G. Sutcliffe, & M. Veanes (Eds.), Processdings of 22nd LPAR (Vol. 57, pp. 36–55). EPiC series in computing.

    Google Scholar 

  • Attamah, M., van Ditmarsch, H., Grossi, D., & van der Hoek, W. (2014). Knowledge and gossip. In Proceedings of 21st ECAI (pp. 21–26). IOS Press.

    Google Scholar 

  • Baker, B., & Shostak, R. (1972). Gossips and telephones. Discrete Mathematics, 2(3), 191–193.

    Google Scholar 

  • Doerr, B., Friedrich, T., & Sauerwald, T. (2014) Quasirandom rumor spreading. ACM Transactions on Algorithms, 11(2), 1–35.

    Google Scholar 

  • Hedetniemi, S. M., Hedetniemi, S. T., & Liestman, A. L. (1988). A survey of gossiping and broadcasting in communication networks. Networks, 18, 319–349.

    Google Scholar 

  • Herzig, A., & Maffre, F. (2017). How to share knowledge by gossiping. AI Communications, 30(1), 1–17.

    Google Scholar 

  • Kermarrec, A. -M., & van Steen, M. (2007) Gossiping in distributed systems. SIGOPS Operating Systems Review, 41(5), 2–7.

    Google Scholar 

  • Tijdeman, R. (1971). On a telephone problem. Nieuw Archief voor Wiskunde, 3(19), 188–192.

    Google Scholar 

  • van Ditmarsch, H., Gattinger, M., Kuijer, L. B., & Pardo, P. (2019). Strengthening gossip protocols using protocol-dependent knowledge. FLAP, 6(1), 157–203. https://arxiv.org/abs/1907.12321.

  • van Ditmarsch, H., van Eijck, J., Pardo, P., Ramezanian, R., & Schwarzentruber, F. (2017). Epistemic protocols for dynamic gossip. Journal of Applied Logic, 20, 1–31.

    Google Scholar 

  • van Ditmarsch, H., van Eijck, J., Pardo, P., Ramezanian, R., & Schwarzentruber, F. (2019). Dynamic gossip. Bulletin of the Iranian Mathematical Society, 45(3), 701–728. https://arxiv.org/abs/1511.00867.

Download references

Acknowledgements

Rasoul Ramezanian and Rahim Ramezanian would like to thank Prof. Ardeshir for his support and encouragement during their Ph.D. research. Hans van Ditmarsch very kindly remembers the fabulous Workshop on Modal Logic and its Application in Computer Science, organized at the University of Tehran in 2016, of which he and Mohammad Ardeshir were co-organizers, and the many interactions over many years involving Rasoul Ramezanian and Rahim Ramezanian, thanks to Mohammad Ardeshir’s encouragement and facilitation. We thank a reviewer of the submission for useful comments.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hans van Ditmarsch .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2021 Springer Nature Switzerland AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

Ramezanian, R., Ramezanian, R., van Ditmarsch, H., Gattinger, M. (2021). Everyone Knows that Everyone Knows. In: Mojtahedi, M., Rahman, S., Zarepour, M.S. (eds) Mathematics, Logic, and their Philosophies. Logic, Epistemology, and the Unity of Science, vol 49. Springer, Cham. https://doi.org/10.1007/978-3-030-53654-1_5

Download citation

Publish with us

Policies and ethics