Cryptology ePrint Archive: BibTeX Citation of Report 2004/151

@misc{cryptoeprint:2004:151,
    author = {Mitsuhiro Haneda and Mitsuru Kawazoe and Tetsuya Takahashi},
    title = {Suitable Curves for Genus-4 HCC over Prime Fields: Point Counting Formulae for Hyperelliptic Curves of type $y^2=x^{2k+1}+ax$},
    howpublished = {Cryptology ePrint Archive, Report 2004/151},
    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.