Cryptology ePrint Archive: BibTeX Citation of Report 2012/594

@misc{cryptoeprint:2012:594,
    author = {Ya Liu and Dawu Gu and Zhiqiang Liu and Wei Li},
    title = {Improved Impossible Differential Attack on Reduced Version of Camellia-192/256},
    howpublished = {Cryptology ePrint Archive, Report 2012/594},
    year = {2012},
    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.