Abstract Prior work suggests that older adults are less aware of potential digital privacy risks compared to younger groups. We seek to expand on these findings by using drawmetrics with 20 older adults (60+) to visualize their experiences with digital privacy via drawing sessions. We further compared older adults with 20 adults of working age (18-59) with the goal of identifying both overlapping concerns and key differences that may be missed when viewing each group in isolation. We extended our evaluation with a survey with questions and themes derived from open-coding of the drawn images and confirmed three key differences between the age groups. These include older adults perceiving a greater threat from using online banking and e-commerce compared to working age adults, older adults exhibiting greater levels of concern about global scale threats, and working age adults showing more privacy-related concern regarding social media. Our findings can be used to potentially tailor applications to better accommodate privacy concerns for older adults.

We report on a qualitative inquiry among security-expert and non-expert mobile device users about the adoption of biometric authentication using semi-structured interviews(n=38, 19/19 expert/non-expert). Security experts more readily adopted biometrics than non-experts but also harbored greater distrust towards its use for sensitive transactions,feared biometric signature compromise, and in some cases distrusted newer facial recognition methods. Both groups harbored misconceptions, such as misunderstanding of the functional role of biometrics in authentication, and were about equally likely to have stopped using biometrics due to usability. Implications include the need for tailored training for security-informed advocates, better design for device sharing and co-registration, and consideration for usability needs in work environments. Refinement of these features would remove perceived obstacles to ubiquitous computing among the growing population of mobile technology users sensitized to security risk.

We analyze the claims that video recreations of shoulder surfing attacks offer a suitable alternative and a baseline, as compared to evaluation in a live setting. We recreated a subset of the factors of a prior video-simulation experiment conducted by Aviv et al. (ACSAC 2017), and model the same scenario using live participants (n = 36) instead (i.e., the victim and attacker were both present). The live experiment confirmed that for Android's graphical patterns video simulation is consistent with the live setting for attacker success rates. However, both 4- and 6-digit PINs demonstrate statistically significant differences in attacker performance, with live attackers performing as much 1.9x better than in the video simulation. The security benefits gained from removing feedback lines in Android's graphical patterns are also greatly diminished in the live setting, particularly under multiple attacker observations, but overall, the data suggests that video recreations can provide a suitable baseline measure for attacker success rate. However, we caution that researchers should consider that these baselines may greatly underestimate the threat of an attacker in live settings.

The purpose of this study is to better understand, from an explorative qualitative perspective, the motivations and practices of highly security-conscious users of mobile authentication, and their underlying mental models of those behaviours. Mobile authentication studies have largely overlooked the mindset of these users in the upper bound of security experience, who have considered their behaviour in terms of detailed knowledge of mobile authentication risk. Twenty IT professionals who self-identified as security-conscious mobile device users, many with decades of intensive security-specific experience, were interviewed for this study regarding their opinions and experiences with mobile device authentication and security. These users described usability and situational impairment issues, as well as a deep concern for their identity and data security arising from highly contextual combinations of distrust towards underlying technologies and situational risk. Derived implications for development of security methods adapted to these informed perspectives are discussed and will be the basis for follow-on research comparing these findings with everyday users.

Given the nature of mobile devices and unlock procedures, unlock authentication is a prime target for credential leaking via shoulder surfing, a form of an observation attack. While the research community has investigated solutions to minimize or prevent the threat of shoulder surfing, our understanding of how the attack performs on current systems is less well studied. In this paper, we describe a large online experiment (n = 1173) that works towards establishing a baseline of shoulder surfing vulnerability for current unlock authentication systems. Using controlled video recordings of a victim entering in a set of 4- and 6-length PINs and Android unlock patterns on different phones from different angles, we asked participants to act as attackers, trying to determine the authentication input based on the observation. We find that 6-digit PINs are the most elusive attacking surface where a single observation leads to just 10.8% successful attacks (26.5% with multiple observations). As a comparison, 6-length Android patterns, with one observation, were found to have an attack rate of 64.2% (79.9% with multiple observations). Removing feedback lines for patterns improves security to 35.3% (52.1% with multiple observations). This evidence, as well as other results related to hand position, phone size, and observation angle, suggests the best and worst case scenarios related to shoulder surfing vulnerability which can both help inform users to improve their security choices, as well as establish baselines for researchers.

This paper describes an exploratory study focusing on the methods of mobile authentication currently utilized by individuals who are blind. Perceptions of security are discussed, along with the trade-offs with usability and accessibility. A tactile aid for a mobile authentication interface was introduced to participants to obtain preliminary feedback on its design. The aid was found to offer promise for supporting orientation, which could be used support novice users, and provide assistance when the mobile device must be used privately in public spaces.

In this paper, we describe an approach to develop alerts for individuals experiencing situationally-induced impairments and disabilities (SIIDs) in inhospitable environments, with a view to support situational awareness and decision making. Our research focuses on the needs of firefighters whose visual and auditory channels may be restricted while performing tasks, resulting in cues sometimes being missed. Through a series of contextual interviews, scenarios have been developed focusing on areas where alerts are required. A participatory-approach has been adopted with the aim of developing perceivable, meaningful and respected alerts, designed to better resist the impacts of SIIDs.

In this paper, we describe a participatory-based approach to developing tactile feedback for a head-mounted device. Three focus groups iteratively designed and evaluated tactile interaction concepts for user-generated use-case scenarios. Results showed productive design insights from the groups regarding approaches to tactile coding schemes addressing the scenario conditions, as well as method-innovations to participatory design techniques for interaction development in unfamiliar sensory modalities such as touch. The study has culminated in the development of a library of tactile icons relating to spatial concepts, which will be tested as part of future work.

In this paper, we describe an exploratory study to determine the feasibility of using a low-cost gestural headset to support communication. Findings have shown tasks involving facial gestures, such as blinks and smiles, can be performed and detected by an Augmented and Alternative Communication (AAC) system within a shorter period of time compared to brow movements. As tasks increase in complexity, rates of accuracy and time taken remain relatively constant for blinking gestures, highlighting their potential in AAC interfaces. We aim to refine such a system to better address the needs of individuals with disabilities, by limiting input errors from involuntary movements and examining ways to reduce interface navigation time. Insights gained from the study offer promise to interface designers seeking to widen access to their interfaces using gestural input.