Cryptology ePrint Archive: BibTeX Citation of Report 2012/395

@misc{cryptoeprint:2012:395,
    author = {Morteza Arifi and Mahmoud Gardeshi and Mohammad Sabzinejad Farash},
    title = {A New Efficient Authenticated ID-Based Group Key Agreement Protocol},
    howpublished = {Cryptology ePrint Archive, Report 2012/395},
    year = {2012},
    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.