Cryptology ePrint Archive: BibTeX Citation of Report 2005/425

@misc{cryptoeprint:2005:425,
    author = {Jie Liang and Xuejia Lai},
    title = {Improved Collision Attack on Hash Function MD5},
    howpublished = {Cryptology ePrint Archive, Report 2005/425},
    year = {2005},
    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.