Cryptology ePrint Archive: BibTeX Citation of Report 2012/654

@misc{cryptoeprint:2012:654,
    author = {Qiang Tang and Yuanjie Zhao and Xiaofeng Chen and Hua Ma},
    title = {Refine the Concept of Public Key Encryption with Delegated Search},
    howpublished = {Cryptology ePrint Archive, Report 2012/654},
    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.