Cryptology ePrint Archive: BibTeX Citation of Report 2004/290

@misc{cryptoeprint:2004:290,
    author = {Wakaha Ogata and Kaoru Kurosawa and Swee-Huay Heng  },
    title = {The Security of the FDH Variant of Chaum's Undeniable Signature Scheme},
    howpublished = {Cryptology ePrint Archive, Report 2004/290},
    year = {2004},
    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.