Cryptology ePrint Archive: BibTeX Citation of Report 2006/135

@misc{cryptoeprint:2006:135,
    author = {Duo Lei, Da Lin2, Li Chao, Keqin Feng, and Longjiang Qu},
    title = {The Design Principle of Hash Function with Merkle-Damg{\aa}rd Construction},
    howpublished = {Cryptology ePrint Archive, Report 2006/135},
    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.