Cryptology ePrint Archive: BibTeX Citation of Report 2012/373

@misc{cryptoeprint:2012:373,
    author = {T-H. Hubert Chan and Elaine Shi and Dawn Song},
    title = {Optimal Lower Bound for Differentially Private Multi-Party Aggregation},
    howpublished = {Cryptology ePrint Archive, Report 2012/373},
    year = {2012},
    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.