Cryptology ePrint Archive: BibTeX Citation of Report 2015/118

@misc{cryptoeprint:2015:118,
    author = {Takahiro Matsuda and Goichiro Hanaoka},
    title = {Constructing and Understanding Chosen Ciphertext Security via Puncturable Key Encapsulation Mechanisms},
    howpublished = {Cryptology ePrint Archive, Report 2015/118},
    year = {2015},
    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.