Cryptology ePrint Archive: BibTeX Citation of Report 2008/537

@misc{cryptoeprint:2008:537,
    author = {SeongHan Shin and Kazukuni Kobara and Hideki Imai},
    title = {A Secure Threshold Anonymous Password-Authenticated Key Exchange Protocol},
    howpublished = {Cryptology ePrint Archive, Report 2008/537},
    year = {2008},
    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.