Cryptology ePrint Archive: BibTeX Citation of Report 2003/248

@misc{cryptoeprint:2003:248,
    author = {Izuru Kitamura and Masanobu Katagi},
    title = {Efficient Implementation of Genus Three Hyperelliptic Curve Cryptography over GF(2^n)},
    howpublished = {Cryptology ePrint Archive, Report 2003/248},
    year = {2003},
    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.