Conference key agreement protocol using oblivious transfer

Ari Moesriami Barmawi, Shingo Takada, Norihisa Doi

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


The basic idea of our protocol is establishing a conference key based on oblivious transfer which can be used in either asymmetric or symmetric cryptography, such that we can reduce the number of decryptions for the key confirmation without sacrificing the level of security. In our proposed method, we break the conference key into several individual secret keys in accordance with the amount of members within the group. This individual key will be used by each member to sign (encrypt (asymmetrically)) the established conference key in the key confirmation procedure. Then, each member multiplies all signed conference keys and decrypting (asymmetrically) the multiplied signed conference key using the multiplicative inverse of his locally calculated conference key. Thus, each member only needs to perform one decryption for the key confirmation. Furthermore, by using the individual secret key, each member can directly communicate with each other by a support of the leader, while the leader does not gain any knowledge of messages which is exchanged between the communicating members. The last features can not be found in the previous method except in Li-Pieprzyk's. However, for the key generation we need only a less modular exponentiations than the former.

Original languageEnglish
Title of host publicationData and Applications Security
Subtitle of host publicationDevelopments and Directions - IFIP TC11 / WG11.3 Fourteenth Annual Working Conference on Database Security
PublisherSpringer New York LLC
Number of pages8
ISBN (Print)0792375149, 9780792375142
Publication statusPublished - 2001 Jan 1
EventIFIP TC11 / WG11.3 14th Annual Working Conference on Database Security - Schoorl, Netherlands
Duration: 2000 Aug 212000 Aug 23

Publication series

NameIFIP Advances in Information and Communication Technology
ISSN (Print)1868-4238


OtherIFIP TC11 / WG11.3 14th Annual Working Conference on Database Security


  • Conference key
  • Individual key
  • Oblivious transfer

ASJC Scopus subject areas

  • Information Systems
  • Computer Networks and Communications
  • Information Systems and Management


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