Paper 2009/423

Utilizing postponed ephemeral and pseudo-static keys in tripartite and identity-based key agreement protocols

Atsushi Fujioka and Koutarou Suzuki and Berkant Ustaoglu

Abstract

We propose an new one-round implicitly authenticated three-party protocol that extends Joux's protocol as well as a two-party identity-based protocol. Our protocols have a single communication round that consists of ephemeral (one-time) public keys along with certificates in the tripartite protocol, and identities in the identity-based setting. As such our protocols are communication efficient and furthermore do not require enhanced message format.