Long-term secure two-round group key establishment from pairings

Abstract

In 2007, Bohli et al. introduced the concept of long-term security as resistance against attacks even if later, after completion of the protocol some security assumptions become invalid, and proposed a three-round long-term secure two-party key establishment protocol. Building on a two-party solution of Bohli et al., we present an authenticated two-round group key establishment protocol which remains secure if either a Computational Bilinear Diffie Hellman problem is hard or a server, who shares a symmetric key with each user, is uncorrupted. © Springer-Verlag Berlin Heidelberg 2014.