Cryptology ePrint Archive: BibTeX Citation of Report 2011/460

@misc{cryptoeprint:2011:460,
    author = {Zijian Zhang and Liehuang Zhu and Lejian Liao},
    title = {Computationally Sound Symbolic Security Reduction Analysis of Group Key Exchange Protocol using Bilinear Pairings},
    howpublished = {Cryptology ePrint Archive, Report 2011/460},
    year = {2011},
    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.