Cryptology ePrint Archive: BibTeX Citation of Report 2013/030

@misc{cryptoeprint:2013:030,
    author = {Haiyan Sun},
    title = {On the security of an identity-based authenticated group key agreement protocol for imbalanced mobile networks},
    howpublished = {Cryptology ePrint Archive, Report 2013/030},
    year = {2013},
    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.