Cryptology ePrint Archive: BibTeX Citation of Report 2005/421

@misc{cryptoeprint:2005:421,
    author = {Michael Backes and Birgit Pfitzmann and Andre Scedrov},
    title = {Key-dependent Message Security under Active Attacks -- BRSIM/UC-Soundness of Symbolic Encryption with Key Cycles},
    howpublished = {Cryptology ePrint Archive, Report 2005/421},
    year = {2005},
    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.