Cryptology ePrint Archive: BibTeX Citation of Report 2007/129

@misc{cryptoeprint:2007:129,
    author = {Cameron McDonald, Chris Charnes, Josef Pieprzyk},
    title = {An Algebraic Analysis of Trivium Ciphers based on the Boolean Satisfiability Problem},
    howpublished = {Cryptology ePrint Archive, Report 2007/129},
    year = {2007},
    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.