Paper 2007/439

Multiparty Key Agreement Using Bilinear Map

Nam-Su Jho, Myung-Hwan Kim, Do Won Hong, and Byung-Gil Lee

Abstract

A key agreement protocol is a cryptographical primitive which allows participants to share a common secret key via insecure channel. In particular, a multiparty key agreement protocol is a key agreement protocol that can manage arbitrary number of participants at once. In the security point of view, authentication and forward secrecy are the most important requirements in such protocols. One interesting problem in key agreement protocols is to construct a multiparty key agreement protocol satisfying the above security requirements with minimal number of communication rounds (i.e. one-round). In literature, there has been no one-round multiparty key agreement protocol that satisfies both of authentication and forward secrecy. In this paper, we present a new multiparty key agreement protocol using bilinear map and adopting the key generation center. The protocol demands only one round for arbitrary number of participants to share a group key and satisfies both authentication and (partial) forward secrecy.