Cryptology ePrint Archive: BibTeX Citation of Report 2015/343

@misc{cryptoeprint:2015:343,
    author = {Michael Düll and Björn Haase and Gesine Hinterwälder and Michael Hutter and Christof Paar and Ana Helena Sánchez and Peter Schwabe},
    title = {High-speed Curve25519 on 8-bit, 16-bit, and 32-bit microcontrollers},
    howpublished = {Cryptology ePrint Archive, Report 2015/343},
    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.