Cryptology ePrint Archive: BibTeX Citation of Report 2006/481

@misc{cryptoeprint:2006:481,
    author = {Donghoon Chang},
    title = {A Practical Limit of Security Proof in the Ideal Cipher Model : Possibility of Using the Constant As a Trapdoor In Several Double Block Length Hash Functions},
    howpublished = {Cryptology ePrint Archive, Report 2006/481},
    year = {2006},
    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.