Faces and Pictures: Understanding age differences in two types of graphical authentications

• Younger and older adults learned faces or picture codes to recall over three weeks.
• Graphical authentication systems are not optimal for older users in their current state.
• Older adults fared better with the faces over pictures while younger adults were reversed.
• Binding of codes was problematic for older adults, suggests a need for exclusive images.

Recall of knowledge-based authentication codes such as passwords and PINs can be problematic, particularly for older adults given the known memory decline associated with ageing. We explored the extent to which recognition-based Graphical Authentication Systems were effective alternatives to PINs and passwords in a study in which users were asked to commit several different codes to memory and recall them at different time periods. Populations of younger and older adults were given face-based and picture-based authentication codes to remember over the course of three weeks. Results show a pronounced age effect, with younger participants outperforming older participants. Older participants fared better with the face-based system over the picture-based system while younger participants exhibited the opposite effect. A significant performance drop was observed for older participants over time, as additional codes were introduced.