Cryptology ePrint Archive: BibTeX Citation of Report 2010/519

@misc{cryptoeprint:2010:519,
    author = {Matthias Krause and Frederik Armknecht and Ewan Fleischmann},
    title = {Preimage Resistance Beyond the Birthday Bound: Double-Length Hashing Revisited},
    howpublished = {Cryptology ePrint Archive, Report 2010/519},
    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.