Understanding the Design Space of Embodied Passwords based on Muscle Memory

Passwords have become a ubiquitous part of our everyday lives, needed for every web-service and system. However, it is challenging to create safe and diverse alphanumeric passwords, and to recall them, imposing a cognitive burden on the user. Through consecutive experiments, we explored the movement space, afordances and interaction, and memorability of a tangible, handheld, embodied password. In this context, we found that: (1) a movement space of 200mm 200mmis preferred; (2) each context has a perceived level of safety, which-together with the afordances and link to familiarity-infuences how the password is performed. Furthermore, the artefact's dimensions should be balanced within the design itself, with the user, and the context, but there is a trade-of between the perceived safety and ergonomics; and (3) the designed embodied passwords can be recalled for at least a week, with participants creating unique passwords which were reproduced consistently.