Cryptology ePrint Archive: BibTeX Citation of Report 2003/191

@misc{cryptoeprint:2003:191,
    author = {David Naccache and Nigel Smart and Jacques Stern},
    title = {Projective Coordinates Leak},
    howpublished = {Cryptology ePrint Archive, Report 2003/191},
    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.