Cryptology ePrint Archive: BibTeX Citation of Report 2000/066

@misc{cryptoeprint:2000:066,
    author = {Birgit Pfitzmann and Michael Waidner},
    title = {A Model for Asynchronous Reactive Systems and its Application to Secure Message Transmission},
    howpublished = {Cryptology ePrint Archive, Report 2000/066},
    year = {2000},
    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.