Multi-party computation based on physical coins

Yuichi Komano, Takaaki Mizuki

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

3 Citations (Scopus)


In the history of cryptography, many cryptographic protocols rely on random coin tosses to discuss their provable security. Although flipping coins is indispensable in this manner, the coins themselves have never been in the spotlight. Therefore, we would like to make physical coins go up to the stage of cryptography, as a deck of physical playing cards has been used to perform a secure multi-party computation. Such a card-based protocol is helpful both to perform a secure computation without any black-box computers and to understand the principles of secure protocols. In this paper, we propose a new framework of secure multi-party computation using physical coins, named a coin-based protocol. Whereas a face-down card can conceal the information about its face side, one side of a coin leaks the information of its other side. Hence, more careful design is required for a secure coin-based protocol than the card-based one. We introduce a computational model of the coin-based protocol and explicitly give protocols for NOT, AND, and copy computations. We also discuss how to implement the protocols in practice.

Original languageEnglish
Title of host publicationTheory and Practice of Natural Computing - 7th International Conference, TPNC 2018, Proceedings
EditorsCarlos Martín-Vide, Miguel A. Vega-Rodríguez, David Fagan, Michael O’Neill
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783030040697
Publication statusPublished - 2018
Event7th International Conference on the Theory and Practice of Natural Computing, TPNC 2018 - Dublin, Ireland
Duration: 2018 Dec 122018 Dec 14

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume11324 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference7th International Conference on the Theory and Practice of Natural Computing, TPNC 2018


  • Card-based protocol
  • Multi-party computation
  • Physical coin


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