Accessible authentication : Assessing the applicability for users with disabilities

Access to the many benefits available from digital technology can often vary depending upon the capabilities and facilities of the individual who is attempting to engage with it. Many digital devices and services require us to be identified and so require some form of user authentication as part of the process. However, the authentication methods that are currently dominant can prove difficult to use and do not meet the needs of users with disabilities. As such, they can constitute an additional barrier that is not faced by other users. This paper presents an assessment of different forms of user authentication (including various forms of secret, token and biometric approaches) against a range of potential disability categories that may affect their suitability for related user communities. The study draws upon disability classification identified by the World Health Organization and analyses how the usability and/or security of current authentication methods fail users with disabilities due to their non-inclusive design. The discussion is based upon a combination of literature review and examination of real-life examples, and identifies aspects of current implementations that can cause problems in different scenarios. The findings suggest that biometric approaches are likely to be more directly applicable without incurring additional overheads, although even here the potential usability impacts are more prominent for some forms of disability. It is further recognised that while some methods can be made more accessible via assistive technologies, the primary aim should be for authentication choices to be as inclusive as possible by default, rather than expecting or requiring that some user groups should face an additional challenge to accessibility.