Browsing by Author "Namara, Moses"
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Item Balancing Security and Usability in Encrypted Email(IEEE Internet Computing, 2017) Bai, Wei; Kim, Doowon; Namara, Moses; Qian, Yichen; Gage Kelley, Patrick; Mazurek, Michelle L.End-to-end encryption is the best way to protect digital messages. Historically, end-to-end encryption has been difficult for people to use, but recent tools have made it more broadly accessible, largely by employing key-directory services. These services sacrifice some security properties for convenience. A 52-person user study found that participants could learn to understand properties of different encryption models and make coherent assessments about when different trade offs might be appropriate. Participants recognized that a less convenient key exchange model was more secure overall, but considered the key-directory approach to have security sufficient for most everyday purposes.Item Cross-Cultural Perspectives on eHealth Privacy in Africa(Thriving Communities, 2018) Namara, Moses; Wilkinson, Daricia; Byron M., Lowens; Knijnenburg, Bart P.; Orji, Rita; Sekou, Remy L.The African continent is making considerable strides to develop and implement technology-driven health innovations. Policymakers are increasingly acknowledging the rising concerns for online personal privacy and data protection as advances in eHealth results in increased levels of data collection and surveillance. In this paper, we propose a research agenda to investigate the effect of cultural, constitutional, and societal factors on privacy concerns and preferences among the different African countries in the context of healthcare technologies. In addition to helping us understand policy and design implications for members of this region, this research will broaden our understanding of cultural factors influencing privacy worldwide.Item The Effectiveness of Adaptation Methods in Improving User Engagement and Privacy Protection on Social Network Sites(Proceedings on Privacy Enhancing Technologies, 2021) Namara, Moses; Sloan, Henry; Knijnenburg, Bart P.Research finds that the users of Social Networking Sites (SNSs) often fail to comprehensively engage with the plethora of available privacy features— arguably due to their sheer number and the fact that they are often hidden from sight. As different users are likely interested in engaging with different subsets of privacy features, an SNS could improve privacy management practices by adapting its interface in a way that proactively assists, guides, or prompts users to engage with the subset of privacy features they are most likely to benefit from. Whereas recent work presents algorithmic implementations of such privacy adaptation methods, this study investigates the optimal user interface mechanism to present such adaptations. In particular, we tested three proposed “adaptation methods” (automation, suggestions, highlights) in an online betweensubjects user experiment in which 406 participants used a carefully controlled SNS prototype. We systematically evaluate the effect of these adaptation methods on participants’ engagement with the privacy features, their tendency to set stricter settings (protection), and their subjective evaluation of the assigned adaptation method. We find that the automation of privacy features afforded users the most privacy protection, while giving privacy suggestions caused the highest level of engagement with the features and the highest subjective ratings (as long as awkward suggestions are avoided). We discuss the practical implications of these findings in the effectiveness of adaptations improving user awareness of, and engagement with, privacy features on social media.Item Emotional and Practical Considerations Towards the Adoption and Abandonment of VPNs as a Privacy-Enhancing Technology(Proceedings on Privacy Enhancing Technologies, 2020) Namara, Moses; Wilkinson, Daricia; Caine, Kelly; Knijnenburg, Bart P.Virtual Private Networks (VPNs) can help people protect their privacy. Despite this, VPNs are not widely used among the public. In this survey study about the adoption and usage of VPNs, we investigate people’s motivation to use VPNs and the barriers they encounter in adopting them. Using data from 90 technologically savvy participants, we find that while nearly all (98%; 88) of the participants have knowledge about what VPNs are, less than half (42%; 37) have ever used VPNs primarily as a privacy-enhancing technology. Of these, 18% (7) abandoned using VPNs while 81% (30) continue to use them to protect their privacy online. In a qualitative analysis of survey responses, we find that people who adopt and continue to use VPNs for privacy purposes are primarily motivated by emotional considerations, including the strong desire to protect their privacy online, wide fear of surveillance and data tracking not only from Internet service providers (ISPs) but also governments and Internet corporations such as Facebook and Google. In contrast, people who are mainly motivated by practical considerations are more likely to abandon VPNs, especially once their practical need no longer exists. These people cite their access to alternative technologies and the effort required to use a VPN as reasons for abandonment. We discuss implications of these findings and provide suggestions on how to maximize adoption of privacy-enhancing technologies such as VPNs, focusing on how to align them with people’s interests and privacy risk evaluation.Item An Inconvenient Trust: User Attitudes Toward Security and Usability Tradeoffs for Key-Directory Encryption Systems(USENIX, 2016) Bai, Wei; Kim, Doowon; Namara, Moses; Qian, Yichen; Gage Kelley, Patrick; Mazurek, Michelle L.Many critical communications now take place digitally, but recent revelations demonstrate that these communications can often be intercepted. To achieve true message privacy, users need end-to-end message encryption, in which the communications service provider is not able to decrypt the content. Historically, end-to-end encryption has proven extremely difficult for people to use correctly, but recently tools like Apple’s iMessage and Google’s End-to-End have made it more broadly accessible by using key-directory services. These tools (and others like them) sacrifice some security properties for convenience, which alarms some security experts, but little is known about how average users evaluate these tradeoffs. In a 52-person interview study, we asked participants to complete encryption tasks using both a traditional key-exchange model and a key-directory-based registration model. We also described the security properties of each (varying the order of presentation) and asked participants for their opinions. We found that participants understood the two models well and made coherent assessments about when different tradeoffs might be appropriate. Our participants recognized that the less-convenient exchange model was more secure overall, but found the security of the registration model to be “good enough” for many everyday purposes.Item The Potential for User-Tailored Privacy on Facebook(IEEE, 2018) Namara, Moses; Sloan, Henry; Jaiswal, Priyanka; Knijnenburg, Bart P.Research shows that Facebook users differ extensively in their use of various privacy features, and that they generally find it difficult to translate their desired privacy preferences into concrete interface actions. Our work explores the use of User-Tailored Privacy (UTP) to adapt Facebook’s privacy features to the user’s personal preferences. We developed adaptive versions of 19 Facebook privacy features, and for each feature we test three adaptation methods (Automation, Highlight and Suggestion) that can be used to implement the adaptive behavior. In a “think-aloud” semistructured interview study (N=18), we show participants paper prototypes of our adaptive privacy features and ask participants to judge the presented adaptive capabilities and the three adaptation methods that implement them. Our findings provide insights into the viability of User-Tailored Privacy. Specifically, we find that the optimal adaptation method depends on the users’ familiarity with the privacy feature and how they use them, and their judgment of the awkwardness and irreversibility of the implemented privacy functionality. We conclude with design recommendations for the implementation of User-Tailored Privacy on Facebook and other social network platforms.Item Privacy at a Glance: The User-Centric Design of Glanceable Data Exposure Visualizations(Proceedings on Privacy Enhancing Technologies, 2020) Wilkinson, Daricia; Bahirat, Paritosh; Namara, Moses; Lyu, Jing; Alsubhi, Arwa; Qiu, Jessica; Wisniewski, Pamela; Knijnenburg, Bart P.Smartphone users are often unaware of mobile applications’ (“apps”) third-party data collection and sharing practices, which put them at higher risk of privacy breaches. One way to raise awareness of these practices is by providing unobtrusive but pervasive visualizations that can be presented in a glanceable manner. In this paper, we applied Wogalter et al.’s Communication-Human Information Processing model (C-HIP) to design and prototype eight different visualizations that depict smartphone apps’ data sharing activities. We varied the granularity and type (i.e., datacentric or app-centric) of information shown to users and used the screensaver/lock screen as a design probe. Through interview-based design probes with Android users (n=15), we investigated the aspects of the data exposure visualizations that influenced users’ comprehension and privacy awareness. Our results shed light on how users’ perceptions of privacy boundaries influence their preference regarding the information structure of these visualizations, and the tensions that exist in these visualizations between glanceability and granularity.We discuss how a pervasive, soft paternalistic approach to privacy-related visualization may raise awareness by enhancing the transparency of information flow, thereby, unobtrusively increasing users’ understanding of data sharing practices of mobile apps. We also discuss implications for privacy research and glanceable security.Item Social media’s have-nots: an era of social disenfranchisement(Internet Research, 2018) Page, Xinru; Wisniewski, Pamela; Knijnenburg, Bart P.; Namara, MosesThe purpose of this paper is to investigate the motivations, concerns, benefits and consequences associated with non-use of socialmedia. In doing so, it extends Wyatt’s commonly used taxonomy of non-use by identifying new dimensions in which to understand non-use of social media. This framework encompasses a previously unidentified category of non-use that is critical to understand in today’s social media environment. Design/methodology/approach – This is an exploratory interview study with 17 self-identified social media non-users distributed across age groups and socioeconomic backgrounds. A thematic analysis is conducted based on a novel extension of Wyatt’s framework and the risk-benefits framework. This is supplemented by open coding to allow for emerging themes. Findings – This paper provides empirical insights into a formerly uninvestigated population of non-users who are prevented from using social media because of social engagement (rather than functional) barriers. It identifies how these individuals face social consequences both on and off social media, resulting in social disenfranchisement. Research limitations/implications – This is an initial exploration of the phenomenon using an interview study. For generalizability, future research should investigate non-use with a broader and random sample. Practical implications – This paper includes design recommendations and implications for social media platform designers to mitigate the consequences experienced by socially disenfranchised non-users. Social implications – Addressing concerns of this newly identified class of non-users is of utmost importance. As others are increasingly connected, these non-users are left behind and even ostracized – showing the dark sides of social media use and non-use. Originality/value – This work identifies types of non-use of social media previously unrecognized in the literature.