Cryptology ePrint Archive: BibTeX Citation of Report 2015/108

@misc{cryptoeprint:2015:108,
    author = {Lucjan Hanzlik and  Przemys{\l}aw Kubiak and Miros{\l}aw Kuty{\l}owski},
    title = {TRACING ATTACKS ON U-PROVE WITH REVOCATION MECHANISM},
    howpublished = {Cryptology ePrint Archive, Report 2015/108},
    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.