Cryptology ePrint Archive: BibTeX Citation of Report 2011/324

@misc{cryptoeprint:2011:324,
    author = {Samuel Ranellucci and Alain Tapp and Severin Winkler and Jürg Wullschleger},
    title = {On the Efficiency of Bit Commitment Reductions},
    howpublished = {Cryptology ePrint Archive, Report 2011/324},
    year = {2011},
    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.