Knowledge-based authentication is almost ubiquitous due to low cost and relatively straightforward implementation. Despite its popularity, there are some well-known problems associated with knowledge-based authentication, such as the cognitive load of memorising multiple codes. As people age and their memory declines, remembering multiple codes is even more challenging. Due to lack of objective evidence regarding the performance of older adults with existing knowledge-based systems, a study was carried out where younger and older participants were required to learn and remember multiple PIN codes and their performance was evaluated over a three-week period. The results from this PIN study demonstrated a clear age effect where younger participants performed significantly more accurately and faster than the older participants. These results reiterated the need for authentication systems that are inclusive of older users and provided a benchmark performance measure for future evaluations. In the next phase four graphical authentication systems (GAS) were evaluated with younger and older adults using the same methodology as the PIN study to determine whether any of them were an improvement. The first system, Tiles, was based on a single image and participants were required to recognise segments of their image from segments taken from other images and yielded disappointing results where overall performance was not an improvement over that of PINs. The second and third systems tested were picture-based and face-based recognition systems. The performance of older participants was promising, especially with the face-based system but the systems could be improved to be more suitable for older users. In the final study, the face-based system was improved by using old faces and ensuring that no two codes shared a face. The results from the final face-based system provide preliminary evidence that a graphical authentication system that is inclusive of older adults may be achievable if designed correctly.
|Publication status||In preparation - 2012|