Cryptology ePrint Archive: BibTeX Citation of Report 2007/219

@misc{cryptoeprint:2007:219,
    author = {Liufei Wu1, 2, Yuqing Zhang1, Fengjiao Wang1},
    title = {A New Provably Secure Authentication and Key Agreement Protocol for SIP Using ECC},
    howpublished = {Cryptology ePrint Archive, Report 2007/219},
    year = {2007},
    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.