Cryptology ePrint Archive: BibTeX Citation of Report 2007/438

@misc{cryptoeprint:2007:438,
    author = {Alexandra Boldyreva and Craig Gentry and Adam O'Neill and Dae Hyun Yum},
    title = {Ordered Multisignatures and Identity-Based Sequential Aggregate Signatures, with Applications to Secure Routing},
    howpublished = {Cryptology ePrint Archive, Report 2007/438},
    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.