Cryptology ePrint Archive: BibTeX Citation of Report 2010/258

@misc{cryptoeprint:2010:258,
    author = {Ruchi Gode and Sugata Gangopadhyay},
    title = {On  lower bounds of second-order nonlinearities of cubic bent functions constructed by concatenating Gold functions},
    howpublished = {Cryptology ePrint Archive, Report 2010/258},
    year = {2010},
    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.