Provably secure identity-based key agreement protocols under simple assumption

In this paper, we present a two-party identity-based key agreement protocol, which is provably secure without random oracles under three static assumptions. It is inspired on a new identity-based encrypt system proposed in TCC 2010 by Lewko and Waters. We show how this key agreement can be used in either escrowed or escrowless mode. We also modify the protocol in the escrow to provide perfect forward secrecy property.