A Collaborative Conference Key Agreement Scheme by Using an Intermediary Node

Conference key agreement is one of the important issues in cryptography. In this paper, we propose a novel conference key agreement scheme. Without adopting the authenticated broadcasting channel model, we use an intermediary node to ensure the correctness of the transmitted messages. A passive adversary or an active adversary obtains zero knowledge about the common conference key established by the all honest participants who follow the proposed scheme. Keywords: conference key, Diffie-Hellman, passive adversary, active adversary, cryptography