Cryptology ePrint Archive: BibTeX Citation of Report 2008/409

@misc{cryptoeprint:2008:409,
    author = {Jun Kurihara and Shinsaku Kiyomoto and Kazuhide Fukushima and Toshiaki Tanaka},
    title = {A New $(k,n)$-Threshold Secret Sharing Scheme and Its Extension},
    howpublished = {Cryptology ePrint Archive, Report 2008/409},
    year = {2008},
    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.