Cryptology ePrint Archive: BibTeX Citation of Report 2009/458

@misc{cryptoeprint:2009:458,
    author = {Wei Yun and Xiong Guo-hua and Zhang Xing-kai and Bao Wan-su},
    title = {Security Analysis and Design of Proxy Signature Schemes over Braid Groups},
    howpublished = {Cryptology ePrint Archive, Report 2009/458},
    year = {2009},
    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.