@misc{cryptoeprint:2006:348,
    author = {Krzysztof Pietrzak},
    title = {Non-Trivial Black-Box Combiners for Collision-Resistant Hash-Functions don't Exist},
    howpublished = {Cryptology ePrint Archive, Report 2006/348},
    year = {2006},
    url = {http://eprint.iacr.org/2006/348},
}