Cryptology ePrint Archive: BibTeX Citation of Report 2009/338

@misc{cryptoeprint:2009:338,
    author = {*Jue-Sam Chou1, Chun-Hui Huang2, Cheng-Chung Ding3},
    title = {Security weaknesses in two multi-server password based authentication protocols},
    howpublished = {Cryptology ePrint Archive, Report 2009/338},
    year = {2009},
    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.