Cryptology ePrint Archive: BibTeX Citation of Report 2015/566

@misc{cryptoeprint:2015:566,
    author = {Nuttapong Attrapadung, Goichiro Hanaoka, Shota Yamada},
    title = {A Framework for Identity-Based Encryption with  Almost Tight Security},
    howpublished = {Cryptology ePrint Archive, Report 2015/566},
    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.