@techreport{bcrrv07,
  author =       {Lujo Bauer and Lorrie Cranor and Robert W. Reeder and Michael K. Reiter and Kami Vaniea},
  title =        {Comparing access-control technologies: A study of keys and smartphones},
  institution =  {CyLab, Carnegie Mellon University},
  month =        feb,
  year =         2007,
  number =       {CMU-CYLAB-07-005},
  url =          {https://www.cylab.cmu.edu/default.aspx?id=2284}
}