@misc{Rivest-2016-Keys-Under-Doormats,
  author =       { Ronald L. Rivest },
  title =        { Keys Under Doormats },
  howpublished = { Invited ("surprise speaker") talk given at the Enigma Conference (San Francisco) },
  date =         { 2016-01-27 },
  OPTmonth =     { January 27, },
  OPTyear =      { 2016 },
  urla =         { <a href="https://www.usenix.org/conference/enigma2016">conference</a>
}