Cryptology ePrint Archive: BibTeX Citation of Report 2008/388

@misc{cryptoeprint:2008:388,
    author = {Christophe Doche and David R. Kohel and Francesco Sica},
    title = {Double-Base Number System for Multi-Scalar Multiplications},
    howpublished = {Cryptology ePrint Archive, Report 2008/388},
    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.