Authenticated Diffie-Hellman Key Exchange with Forward Secrecy

Forward secrecy is an important security property in key agreement protocol. Based on Harn's protocol, in this paper a new authenticated Diffie-Hellman key agreement protocol with half forward secrecy is proposed. This protocol is also based on a single cryptographic assumption, and is user authentication and shared key authentication. More importantly, our protocol provides forward secrecy with respect to one of the parties. For this reason, besides the advantages of Harn's rotocol, in practice, our protocol can reduce the damages resulted from the disclosure of the user's secret key and it is very beneficial to today's communication with portable devices.