“…So far, several research works on public-key based remote user authentication (Chang and Wu, 1993;Chang and Liao, 1994;Hwang and Yeh, 2002;Shen et al, 2003) have been done. Unfortunately, many times, a paper typically breaks a previous scheme and proposes a new one (Ku et al, 2003;Hsieh et al, 2003), which someone breaks later and, in turn, proposes a new one, and so on. Most of such work, though quite important and useful, essentially provides an incremental advance to the same basic theme (Peyravian and Zunic, 2000).…”