Cryptology ePrint Archive: BibTeX Citation of Report 2004/308

@misc{cryptoeprint:2004:308,
    author = {Guohong Xie},
    title = {Cryptanalysis of Noel McCullagh and Paulo S. L. M. Barreto¡¯s two-party identity-based key agreement},
    howpublished = {Cryptology ePrint Archive, Report 2004/308},
    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.