@misc{cryptoeprint:2009:477,
    author = {Jian Guo and Krystian Matusiewicz},
    title = {Preimages for Step-Reduced SHA-2},
    howpublished = {Cryptology ePrint Archive, Report 2009/477},
    year = {2009},
    url = {http://eprint.iacr.org/2009/477},
}