Cryptology ePrint Archive: BibTeX Citation of Report 2015/043

@misc{cryptoeprint:2015:043,
    author = {Ai Ishida, Keita Emura, Goichiro Hanaoka, Yusuke Sakai, and Keisuke Tanaka},
    title = {Group Signature with Deniability: How to Disavow a Signature},
    howpublished = {Cryptology ePrint Archive, Report 2015/043},
    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.