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.