  This paper describes a new password-based mutual authentication protocol for
Web systems which prevents various kinds of phishing attacks. This protocol
provides a protection of user's passwords against any phishers even if
dictionary attack is employed, and prevents phishers from imitating a false
sense of successful authentication to users. The protocol is designed
considering interoperability with many recent Web applications which requires
many features which current HTTP authentication does not provide. The protocol
is proposed as an Internet Draft submitted to IETF, and implemented in both
server side (as an Apache extension) and client side (as a Mozilla-based
browser and an IE-based one). The paper also proposes a new user-interface for
this protocol which is always distinguishable from fake dialogs provided by
phishers.
