On cheater identifiable secret sharing schemes secure against rushing adversary

Rui Xu, Kirill Morozov, Tsuyoshi Takagi

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

11 Citations (Scopus)


At EUROCRYPT 2011, Obana proposed a k-out-of-n secret sharing scheme capable of identifying up to t cheaters with probability 1 - ε under the condition t < k/3. In that scheme, the share size |Vi| satisfies |Vi| = |S|/ε, which is almost optimal. However, Obana's scheme is known to be vulnerable to attacks by rushing adversary who can observe the messages sent by the honest participants prior to deciding her own messages. In this paper, we present a new scheme, which is secure against rushing adversary, with |Vi| = |S|/εn-t+1, assuming t < k/3. We note that the share size of our proposal is substantially smaller compared to |V i| = |S|(t + 1)3n3n in the scheme by Choudhury at PODC 2012 when the secret is a single field element. A modification of the later scheme is secure against rushing adversary under a weaker t < k/2 condition. Therefore, our scheme demonstrates an improvement in share size achieved for the price of strengthening the assumption on t.

Original languageEnglish
Title of host publicationAdvances in Information and Computer Security - 8th International Workshop on Security, IWSEC 2013, Proceedings
Number of pages14
Publication statusPublished - 2013
Event8th International Workshop on Security, IWSEC 2013 - Okinawa, Japan
Duration: Nov 18 2013Nov 20 2013

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume8231 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other8th International Workshop on Security, IWSEC 2013

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • Computer Science(all)


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