A provable secure ID-based explicit authenticated key agreement protocol without random oracles

In this paper, we present an identity-based explicit authenticated key agreement protocol that is provably secure without random oracles. The protocol employs a new method to isolate a session key from key con¯rmation keys so that there is no direct usage of hash functions in the protocol. The protocol is proved secure without random oracles in a variant of Bellare and Rogaway style model, an exception to current proof method in this style model in the ID-based setting. We believe that this key isolation method is novel and can be further studied for constructing more e±cient protocols.