Cryptology ePrint Archive: BibTeX Citation of Report 2015/616

@misc{cryptoeprint:2015:616,
    author = {Lukasz Olejnik and Gunes Acar and Claude Castelluccia and Claudia Diaz},
    title = {The leaking battery: A privacy analysis of the HTML5 Battery Status API},
    howpublished = {Cryptology ePrint Archive, Report 2015/616},
    year = {2015},
    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.