Cryptology ePrint Archive: BibTeX Citation of Report 2013/180

@misc{cryptoeprint:2013:180,
    author = {Masao KASAHARA},
    title = {A New Class of Product-sum Type Public Key Cryptosystem,K(V)$\Sigma\Pi$PKC,Constructed Based on Maximum Length Code},
    howpublished = {Cryptology ePrint Archive, Report 2013/180},
    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.