Long-Term Secure Asymmetric Group Key Agreement

Abstract

AbstractA group key agreement protocol allows a set of users to share a common secret in presence of adversaries. In symmetric group key agreement protocol, the set of users will have a secret key at the end of protocol while in an asymmetric group key agreement protocol, the set of users negotiate a shared encryption and decryption keys, instead of establishing a common secret. Long-term security is a notion of resistance against attacks even if later, after completion of the protocol some security assumptions become invalid. In this paper, we propose a long-term secure one-round asymmetric group key agreement protocol. Our protocol is based on Bilinear Diffie-Hellman assumption and real-or random indistinguishability of the symmetric encryption scheme. For authentication purpose we use a signature scheme and timestamps.KeywordsLong-term securityBilinear Diffie-Hellman assumptionGroup key agreement