Cryptology ePrint Archive: BibTeX Citation of Report 2014/849

@misc{cryptoeprint:2014:849,
    author = {Ryotaro Hayashi and Tatsuyuki Matsushita},
    title = {A Proxy Re-Encryption Scheme with the Unforgeability of Re-Encryption Keys against Collusion Attacks},
    howpublished = {Cryptology ePrint Archive, Report 2014/849},
    year = {2014},
    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.