Cryptology ePrint Archive: BibTeX Citation of Report 2013/438

@misc{cryptoeprint:2013:438,
    author = {Johann Heyszl and Andreas Ibing and Stefan Mangard and Fabrizio De Santis and Georg Sigl},
    title = {Clustering Algorithms for Non-Profiled Single-Execution Attacks on Exponentiations},
    howpublished = {Cryptology ePrint Archive, Report 2013/438},
    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.