Cryptology ePrint Archive: BibTeX Citation of Report 2015/707

@misc{cryptoeprint:2015:707,
    author = {Siamak F. Shahandashti and Reihaneh Safavi-Naini and Nashad Ahmed Safa},
    title = {Reconciling User Privacy and Implicit Authentication for Mobile Devices},
    howpublished = {Cryptology ePrint Archive, Report 2015/707},
    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.