Cryptology ePrint Archive: BibTeX Citation of Report 2009/089

@misc{cryptoeprint:2009:089,
    author = {Boris Köpf and Markus Dürmuth},
    title = {A Provably Secure And Efficient Countermeasure Against Timing Attacks},
    howpublished = {Cryptology ePrint Archive, Report 2009/089},
    year = {2009},
    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.