Assessing Inconspicuous Smartphone Authentication for Blind People
It addresses the challenge of secure and discreet authentication for blind smartphone users, though it is incremental as it builds on existing tap-based methods.
This paper tackled the problem of smartphone authentication for blind users by evaluating a tap-based method, finding it to be usable and supporting inconspicuous behavior in a study with 16 participants.
As people store more personal data in their smartphones, the consequences of having it stolen or lost become an increasing concern. A typical counter-measure to avoid this risk is to set up a secret code that has to be entered to unlock the device after a period of inactivity. However, for blind users, PINs and passwords are inadequate, since entry 1) consumes a non-trivial amount of time, e.g. using screen readers, 2) is susceptible to observation, where nearby people can see or hear the secret code, and 3) might collide with social norms, e.g. disrupting personal interactions. Tap-based authentication methods have been presented and allow unlocking to be performed in a short time and support naturally occurring inconspicuous behavior (e.g. concealing the device inside a jacket) by being usable with a single hand. This paper presents a study with blind users (N = 16) where an authentication method based on tap phrases is evaluated. Results showed the method to be usable and to support the desired inconspicuity.