Cryptology ePrint Archive: BibTeX Citation of Report 2003/054

@misc{cryptoeprint:2003:054,
    author = {Ryuichi SAKAI and Masao KASAHARA},
    title = {ID based Cryptosystems with Pairing on Elliptic Curve},
    howpublished = {Cryptology ePrint Archive, Report 2003/054},
    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.