Constructing optimistic multi-party contract signing protocols

Barbara Kordy*, Saša Radomirović

*Corresponding author for this work

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

9 Citations (Scopus)


We give an explicit, general construction for optimistic multi-party contract signing protocols. Our construction converts a sequence over any finite set of signers into a protocol specification for the signers. The inevitable trusted third party's role specification and computations are independent of the signer's role specification. This permits a wide variety of protocols to be handled equally by the trusted third party. We give tight conditions under which the resulting protocols satisfy fairness and timeliness. We provide examples of several classes of protocols and we discuss lower bounds for the complexity of fair protocols, both in terms of bandwidth and minimum number of messages. Our results highlight the connection between optimistic fair contract signing protocols and the combinatorial problem of constructing sequences which contain all permutations of a set as subsequences. This connection is stronger than was previously realized.

Original languageEnglish
Title of host publication2012 IEEE 25th Computer Security Foundations Symposium
Number of pages15
ISBN (Electronic)9780769547183
ISBN (Print)9781467319188
Publication statusPublished - 13 Aug 2012
Event25th IEEE Computer Security Foundations Symposium 2012 - Cambridge, MA, United States
Duration: 25 Jun 201227 Jun 2012

Publication series

NameProceedings of the Computer Security Foundations Symposium
ISSN (Print)1063-6900
ISSN (Electronic)2377-5459


Conference25th IEEE Computer Security Foundations Symposium 2012
Abbreviated titleCSF 2012
Country/TerritoryUnited States
CityCambridge, MA

ASJC Scopus subject areas

  • Software


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