Cryptology ePrint Archive: BibTeX Citation of Report 2008/044

@misc{cryptoeprint:2008:044,
    author = {Ari Juels and Ravikanth Pappu and Bryan Parno},
    title = {Unidirectional Key Distribution Across Time and Space with Applications to RFID Security},
    howpublished = {Cryptology ePrint Archive, Report 2008/044},
    year = {2008},
    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.