Cryptology ePrint Archive: BibTeX Citation of Report 2015/187

@misc{cryptoeprint:2015:187,
    author = {Juan Garay and Jonathan Katz and Bjoern Tackmann and Vassilis Zikas},
    title = {How Fair is Your Protocol? A Utility-based Approach to Protocol Optimality},
    howpublished = {Cryptology ePrint Archive, Report 2015/187},
    year = {2015},
    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.