Cryptology ePrint Archive: BibTeX Citation of Report 2015/643

@misc{cryptoeprint:2015:643,
    author = {Jonathan Bootle and Andrea Cerulli and Pyrros Chaidos and Essam Ghadafi and Jens Groth and Christophe Petit},
    title = {Short Accountable Ring Signatures Based on DDH},
    howpublished = {Cryptology ePrint Archive, Report 2015/643},
    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.