Paper 2003/190

Extending Joux's Protocol to Multi Party Key Agreement

Rana Barua, Ratna Dutta, and Palash Sarkar

Abstract

We present a secure unauthenticated as well as an authenticated multi party key agreement protocol. The authenticated version of our protocol uses ternary trees and is based on bilinear maps and Joux's three party protocol. The number of rounds, computation/communication complexity of our protocol compares favourably with previously known protocols. The authenticated version of our protocol also uses ternary trees and is based on public IDs and Key Generation Centres. The authenticated version of our protocol is more efficient than all previously known authenticated key agreement protocols.