Cryptology ePrint Archive: BibTeX Citation of Report 2012/136

@misc{cryptoeprint:2012:136,
    author = {Zilong Wang and Danfeng (Daphne) Yao and Rongquan Feng},
    title = {Adaptive Key Protection in Complex Cryptosystems with Attributes},
    howpublished = {Cryptology ePrint Archive, Report 2012/136},
    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.