In search of the silver bullet to solve the password problem, the field of knowledge-based
authentication has become bloated with novel proposals aiming to replace textual …

Unobtrusiveness has been highlighted as an important design principle in Human-
Computer Interaction (HCI). However, the understanding of unobtrusiveness in the literature …

Multi-touch mobile devices have penetrated into everyday life to support personal and
business communications. Secure and usable authentication techniques are indispensable …

This paper presents TapMeIn, an eyes-free, two-factor authentication method for
smartwatches. It allows users to tap a memorable melody (tap-password) of their choice …

To successfully manage security and privacy threats, users must be able to perceive the
relevant information. However, a number of accessibility obstacles impede the access of …

Wearable devices that capture users' rich information regarding their daily activities have
unmet authentication needs. Today's solutions, which primarily rely on indirect …

Smartphones provide access to increasing amounts of personal and sensitive information,
yet are often only secured using methods that are prone to observational attacks. We …

The deployment of NFC technology on mobile phones is gaining momentum, enabling many
important applications such as NFC payments, access control for building or public transit …

Tapping-based rhythmic passwords have recently been proposed for the purpose of user
authentication and device pairing. They offer a usability advantage over traditional …

Pictures are more likely to be remembered than words or text. For smartphone
authentication, graphical password interfaces employing both visual objects and auditory …