Cryptology ePrint Archive: BibTeX Citation of Report 2006/187

@misc{cryptoeprint:2006:187,
    author = {Jongsung Kim and Alex Biryukov and Bart Preneel and Seokhie Hong},
    title = {On the Security of HMAC and NMAC Based on HAVAL, MD4, MD5, SHA-0 and SHA-1},
    howpublished = {Cryptology ePrint Archive, Report 2006/187},
    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.