Cryptology ePrint Archive: BibTeX Citation of Report 2002/191

@misc{cryptoeprint:2002:191,
    author = {Frederik Armknecht},
    title = {A Linearization Attack on the Bluetooth Key Stream Generator},
    howpublished = {Cryptology ePrint Archive, Report 2002/191},
    year = {2002},
    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.