Cryptology ePrint Archive: BibTeX Citation of Report 2007/304

@misc{cryptoeprint:2007:304,
    author = {Simon R. Blackburn, Tuvi Etzion, Douglas R. Stinson and Gregory M. Zaverucha},
    title = {A Bound on the Size of Separating Hash Families},
    howpublished = {Cryptology ePrint Archive, Report 2007/304},
    year = {2007},
    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.