Cryptology ePrint Archive: BibTeX Citation of Report 2015/864

@misc{cryptoeprint:2015:864,
    author = {Christine Jost and Ha Lam and Alexander Maximov and Ben Smeets},
    title = {Encryption Performance Improvements of the Paillier Cryptosystem},
    howpublished = {Cryptology ePrint Archive, Report 2015/864},
    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.