An Efficient Group Key Agreement Protocol from Bilinear Pairings

A group key agreement protocol is designed to efficiently implement secure multicast channels for a group of parties communicating over an distrustful, open network by allowing them to agree on a common secret key. Recently some constant-round protocols have been proposed. However, some of them are too expensive with computational complexity O(n), others with lower computational complexity doesn´t ensure the participants to get the same session key. In this paper we propose a new constant-round protocol suited for groups consisting of many hosts with limited computational capability and a host with more computational power. Then we prove its security.