Cryptology ePrint Archive: BibTeX Citation of Report 2003/238

@misc{cryptoeprint:2003:238,
    author = {Xinjun Du and Ying Wang and 	Jianhua Ge and Yumin Wang},
    title = {Chameleon Signature from Bilinear Pairing},
    howpublished = {Cryptology ePrint Archive, Report 2003/238},
    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.