Cryptology ePrint Archive: BibTeX Citation of Report 2011/090

@misc{cryptoeprint:2011:090,
    author = {Yu Chen and Liqun Chen and Zhong Chen},
    title = {Generic Methods to Achieve Tighter Security Reductions for a Category of IBE Schemes },
    howpublished = {Cryptology ePrint Archive, Report 2011/090},
    year = {2011},
    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.