Cryptology ePrint Archive: BibTeX Citation of Report 2011/040

@misc{cryptoeprint:2011:040,
    author = {Hoon Hong, Eunjeong Lee, Hyang-Sook Lee and Cheol-Min Park},
    title = {Simple and Exact Formula for Minimum Loop Length  in Ate_i  Pairing based on Brezing-Weng Curves},
    howpublished = {Cryptology ePrint Archive, Report 2011/040},
    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.