Cryptology ePrint Archive: BibTeX Citation of Report 1999/021

@misc{cryptoeprint:1999:021,
    author = {Maurizio Kliban Boyarsky },
    title = {Public-Key  Cryptography  and  Password  Protocols:  The Multi-User Case },
    howpublished = {Cryptology ePrint Archive, Report 1999/021},
    year = {1999},
    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.