Contemporary personal mobile devices support a variety of
		  authentication approaches, featuring different levels of
		  security and usability. With cameras embedded in smart
		  glasses, seamless, hands-free mobile authentication based
		  on gaze is possible. Gaze authentication relies on
		  knowledge as a secret, and gaze passwords are composed from
		  a series of gaze points or gaze gestures. This paper
		  investigates the concept of free-form mobile gaze
		  passwords. Instead of relying on gaze gestures or points,
		  free-form gaze gestures exploit the trajectory of the gaze
		  over time. We collect and investigate a set of 29 different
		  free-form gaze passwords from 19 subjects. In addition, the
		  practical security of the approach is investigated in a
		  study with 6 attackers observing eye movements during
		  password input to subsequently perform spoofing. Our
		  investigation indicates that most free-form gaze passwords
		  can be expressed as a set of common geometrical shapes.
		  Further, our free-form gaze authentication yields a true
		  positive rate of 81% and a false positive rate with other
		  gaze passwords of 12%, while targeted observation and
		  spoofing is successful in 17.5% of all cases. Our
		  usability study reveals that further work on the usability
		  of gaze input is required as subjects reported that they
		  felt uncomfortable creating and performing free-form
		  passwords.<br>
<br><pre>@inproceedings{Fristroem_19_FreeFormGaze,
  author = {Fristr\"om, Eira and Lius, Elias and Ulmanen, Niki and Hietala, Paavo and K\"arkk\"ainen, Pauliina and M\"akinen, Tommi and Sigg, Stephan and Findling, Rainhard Dieter},
  booktitle = {Proc. {MoMM} 2019: 17th International Conference on
  		  Advances in Mobile Computing and Multimedia},
  title = {Free-Form Gaze Passwords from Cameras Embedded in Smart
  		  Glasses},
  year = {2019},
  month = dec,
  number = { {In print}},
  publisher = {ACM}
}
</pre>