Cryptology ePrint Archive: BibTeX Citation of Report 2004/054

@misc{cryptoeprint:2004:054,
    author = {Guilin Wang, Feng Bao, Jianying Zhou, and Robert H. Deng},
    title = {Comments on a Threshold Proxy Signature Scheme Based on the RSA Cryptosystem},
    howpublished = {Cryptology ePrint Archive, Report 2004/054},
    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.