@misc{cryptoeprint:2004:033,
author = {Muxiang Zhang},
title = {New Approaches to Password Authenticated Key Exchange based on RSA},
howpublished = {Cryptology ePrint Archive, Report 2004/033},
year = {2004},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.