Cryptology ePrint Archive: BibTeX Citation of Report 2010/574

@misc{cryptoeprint:2010:574,
    author = {Julia Borghoff and Lars R. Knudsen and Gregor Leander and Soeren S. Thomsen},
    title = {Cryptanalysis of PRESENT-like ciphers with secret S-boxes},
    howpublished = {Cryptology ePrint Archive, Report 2010/574},
    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.