Cryptology ePrint Archive: BibTeX Citation of Report 2013/140

@misc{cryptoeprint:2013:140,
    author = {Marc Fischlin and Nils Fleischhacker},
    title = {Limitations of the Meta-Reduction Technique: The Case of Schnorr Signatures},
    howpublished = {Cryptology ePrint Archive, Report 2013/140},
    year = {2013},
    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.