Cryptology ePrint Archive: BibTeX Citation of Report 2004/348

@misc{cryptoeprint:2004:348,
    author = {Junghyun Nam, Seungjoo Kim, and Dongho Won},
    title = {A weakness in Sun-Chen-Hwang's three-party key agreement protocols using passwords},
    howpublished = {Cryptology ePrint Archive, Report 2004/348},
    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.