Cryptology ePrint Archive: BibTeX Citation of Report 2010/261

@misc{cryptoeprint:2010:261,
    author = {Céline Blondeau and Benoît Gérard},
    title = {Links Between Theoretical and Effective Differential Probabilities: Experiments on PRESENT},
    howpublished = {Cryptology ePrint Archive, Report 2010/261},
    year = {2010},
    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.