Users often need to authenticate at situated displays in or- der to, for example, make purchases, access sensitive in- formation, or confirm an identity. However, the exposure of interactions in public spaces introduces a large attack surface (e.g., observation, smudge or thermal attacks).
A plethora of authentication models and input modalities that aim at disguising users’ input has been presented in the past. However, a comprehensive analysis on the re- quirements for secure and usable authentication on public displays is still missing. This work presents 13 design con- siderations suitable to inform practitioners and researchers during the development process of authentication systems for situated displays in public spaces. It draws on a com- prehensive analysis of prior literature and subsequent dis- cussion with five experts in the fields of pervasive displays, human-computer-interaction and usable security.