Cryptology ePrint Archive: BibTeX Citation of Report 2010/006

@misc{cryptoeprint:2010:006,
    author = {Thorsten Kleinjung and Kazumaro Aoki and Jens Franke and Arjen Lenstra and Emmanuel Thomé and Joppe Bos and Pierrick Gaudry and Alexander Kruppa and Peter Montgomery and Dag Arne Osvik and Herman te Riele and Andrey Timofeev and Paul Zimmermann},
    title = {Factorization of a 768-bit RSA modulus},
    howpublished = {Cryptology ePrint Archive, Report 2010/006},
    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.