Password authenticated key exchange protocols among diverse network domains

Up to now, all papers in password-authenticated key exchange protocols are constrained to two-party or three-party models. Under these two models, the clients are registered or authenticated by the same server. However, in reality two communicants may register under two different servers. In this case, the above models are inefficient or not suitable any more. This paper will discuss password authenticated key exchange protocol where both communicants are registered in two distinct servers.