Date Added: Mar 2011
Key Agreement (KA) allows two or more users to negotiate a secret session key among them over an open network. Authenticated Key Agreement (AKA) is a KA protocol enhanced to prevent active attacks. AKA can be achieved using a Public-Key Infrastructure (PKI) or identity-based cryptography. However, the former suffers from a heavy certificate management burden while the latter is subject to the so-called key escrow problem. Recently, certificateless cryptography was introduced to mitigate these limitations. The authors propose an efficient certificateless two-party AKA protocol. Security is proven under the standard Computational Diffie-Hellman (CDH) and Bilinear Diffie-Hellman (BDH) assumptions. The protocol is efficient and practical, because it requires only one pairing operation and three scale multiplications by each party.