Cryptology ePrint Archive: BibTeX Citation of Report 2013/540

@misc{cryptoeprint:2013:540,
    author = {Junghyun Nam and Kim-Kwang Raymond Choo and Juryon Paik and Dongho Won},
    title = {On the security of a password-only authenticated three-party key exchange protocol},
    howpublished = {Cryptology ePrint Archive, Report 2013/540},
    year = {2013},
    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.