Cryptology ePrint Archive: BibTeX Citation of Report 2015/515

@misc{cryptoeprint:2015:515,
    author = {Thomas Espitau and Pierre-Alain Fouque and Pierre Karpman},
    title = {Higher-Order Differential Meet-in-The-Middle Preimage Attacks on SHA-1 and BLAKE},
    howpublished = {Cryptology ePrint Archive, Report 2015/515},
    year = {2015},
    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.