Authenticated key agreement protocol using bilinear aggregate signatures

In this paper, we present a new two-party authenticated key agreement (AK) protocol which is based on two-signer bilinear aggregate signatures. It is inspired by a novel encryption scheme first proposed by Gentry at EuroCrypt'03. In our protocol, the CA and the user sign some different data to corporately generate the user's private key. The basic two-pass protocol and a three-pass protocol with key confirmation are described and their properties are discussed. An important advantage of our protocol is that it preserves the perfect forward secrecy even though the long-term secret key of the TA (Trusted Authority) is compromised. Thus, our protocol achieves TA forward secrecy.