Cryptology ePrint Archive: BibTeX Citation of Report 2010/057

@misc{cryptoeprint:2010:057,
    author = {Cagdas Calik and Meltem Sonmez Turan},
    title = {Message Recovery and Pseudo-Preimage Attacks on the Compression Function of Hamsi-256},
    howpublished = {Cryptology ePrint Archive, Report 2010/057},
    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.