Cryptology ePrint Archive: BibTeX Citation of Report 2005/385

@misc{cryptoeprint:2005:385,
    author = {Giuseppe Ateniese and Jan Camenisch and Susan Hohenberger and Breno de Medeiros},
    title = {Practical Group Signatures without Random Oracles},
    howpublished = {Cryptology ePrint Archive, Report 2005/385},
    year = {2005},
    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.