Cryptology ePrint Archive: BibTeX Citation of Report 2011/031

@misc{cryptoeprint:2011:031,
    author = {Ashish Choudhury and Arpita Patra},
    title = {Efficient Unconditional Asynchronous  Byzantine Agreement with Optimal Resilience},
    howpublished = {Cryptology ePrint Archive, Report 2011/031},
    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.