Cryptology ePrint Archive: Report 2004/127

DDH-based Group Key Agreement in a Mobile Environment

Junghyun Nam, Jinwoo Lee, Seungjoo Kim, and Dongho Won

Abstract: A group key agreement protocol is designed to efficiently implement secure multicast channels for a group of parties communicating over an untrusted, open network by allowing them to agree on a common secret key. In the past decade many problems related to group key agreement have been tackled and solved (diminished if not solved), and recently some constant-round protocols have been proven secure in concrete, realistic setting. However, all forward-secure protocols so far are still too expensive for small mobile devices. In this paper we propose a new constant-round protocol well suited for a mobile environment and prove its security under the Decisional Diffie-Hellman assumption. The protocol meets simplicity, efficiency, and all the desired security properties.

Category / Keywords: cryptographic protocols / group key agreement, multicast, security model, DDH

Date: received 29 May 2004, last revised 7 Dec 2004

Contact author: jhnam at dosan skku ac kr

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Version: 20041208:055645 (All versions of this report)

Short URL: ia.cr/2004/127

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