Provably-secure two-round password-authenticated group key exchange in the standard model

Jeong Ok Kwon, Ik Rae Jeong, Dong Hoon Lee

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

9 Citations (Scopus)


Password-authenticated group key exchange (PAGKE) allows group users to share a session key using a human-memorable password only. The fundamental security goal of PAGKE is security against dictionary attacks. Several solutions have been proposed to solve this problem while most ones require rounds linearly increasing in the number of group users, so they are neither scalable nor practical. Recently a provably-secure constant-round PAGKE protocol overcoming this short- coming is proposed at PKC '06. However current PAGKE protocols have been proven secure in the ideal model. The ideal model assumes that some functions are "ideal" functions (or random functions). In the ideal cipher model, we assume a block cipher is an ideal cipher and in the ideal hash model (also the so-called the random oracle model), we assume a hash function is an ideal hash function. However it is well-known that a provably-secure scheme in the ideal model may be insecure if the ideal functions are implemented by the real functions. In this paper we propose the first provably-secure PAGKE protocol in the standard model. Our protocol is a two-round protocol and the security of the protocol is reduced to the Decisional Diffie-Hellman (DDH) problem.

Original languageEnglish
Title of host publicationAdvances in Information and Computer Security - First International Workshop on Security, IWSEC 2006, Proceedings
PublisherSpringer Verlag
Number of pages15
ISBN (Print)3540476997, 9783540476993
Publication statusPublished - 2006
Event1st International Workshop on Security, IWSEC 2006 - Kyoto, Japan
Duration: 2006 Oct 232006 Oct 24

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4266 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other1st International Workshop on Security, IWSEC 2006

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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