As smart home devices proliferate, protecting the privacy of those who encounter the devices is of the utmost importance both within their own home and in other people's homes. In this study, we conducted a large-scale survey (N=1459) with primary users of and bystanders to smart home devices. While previous work has studied people's privacy experiences and preferences either as smart home primary users or as bystanders, there is a need for a deeper understanding of privacy experiences and preferences in different contexts and across different countries. Instead of classifying people as either primary users or bystanders, we surveyed the same participants across different contexts. We deployed our survey in four countries (Germany, Mexico, the United Kingdom, and the United States) and in two languages (English and Spanish). We found that participants were generally more concerned about devices in their own homes, but perceived video cameras—especially unknown ones—and usability as more concerning in other people's homes. Compared to male participants, female and non-binary participants had less control over configuration of devices and privacy settings—regardless of whether they were the most frequent user. Comparing countries, participants in Mexico were more likely to be comfortable with devices, but also more likely to take privacy precautions around them. We also make cross-contextual recommendations for device designers and policymakers, such as nudges to facilitate social interactions.

Calls for engagement with the public in Artificial Intelligence (AI) research, development, and governance are increasing, leading to the use of surveys to capture people's values, perceptions, and experiences related to AI. In this paper, we critically examine the state of human participant surveys associated with these topics. Through both a reflexive analysis of a survey pilot spanning six countries and a systematic literature review of 44 papers featuring public surveys related to AI, we explore prominent perspectives and methodological nuances associated with surveys to date. We find that public surveys on AI topics are vulnerable to specific Western knowledge, values, and assumptions in their design, including in their positioning of ethical concepts and societal values, lack sufficient critical discourse surrounding deployment strategies, and demonstrate inconsistent forms of transparency in their reporting. Based on our findings, we distill provocations and heuristic questions for our community, to recognize the limitations of surveys for meeting the goals of engagement, and to cultivate shared principles to design, deploy, and interpret surveys cautiously and responsibly.

There has been a growing body of work on migration within the HCI community, as well as within the social science and public policy communities. More specifically, human-centered security researchers have been exploring the needs and concerns of migrants, starting to contend with the harms created by digital technologies and experienced by those who are and have been marginalized. Case studies through which migration and (digital) security within the HCI domain intersect have been localized to specific contexts such as, e.g., particular issues related to data processing and sharing in refugee camps, or a narrow set of security threats and harms experienced by migrant workers in their new places of work. However, more holistic approaches to understanding the intersections of migration and (digital) security are yet to be fully explored while accounting for the past (including home country security practices, use of localized digital technologies, and interactions with technologies throughout the migration journey), the present (current security practices and experiences in the place or country migrants are situated), and the future migrants are trying to secure for themselves and their families. This workshop aims to build a community of HCI researchers interested in how migration and (digital) security intersect to braid together research narratives, perspectives, and methods, design for inclusive technologies, and build an agenda for future research and practice.

While the literature on permissions from the end-user perspective is rich, there is a lack of empirical research on why developers request permissions, their conceptualization of permissions, and how their perspectives compare with end-users’ perspectives. Our study aims to address these gaps using a mixed-methods approach. Through interviews with 19 app developers and a survey of 309 Android and iOS end-users, we found that both groups shared similar concerns about unnecessary permissions breaking trust, damaging the app’s reputation, and potentially allowing access to sensitive data. We also found that developer participants sometimes requested multiple permissions due to confusion about the scope of certain permissions or third-party library requirements. Additionally, most end-user participants believed they were responsible for granting a permission request, and it was their choice to do so, a belief shared by many developer participants. Our findings have implications for improving the permission ecosystem for both developers and end-users.

Globally, countries have been developing contact tracing applications to control the spread of the coronavirus (COVID-19) disease. In this work, we present the findings of eight focus groups we conducted with participants living in France and Germany, to explore why they decided to adopt, or not adopt, a contact tracing application as well as understand how they perceived the benefits, drawbacks, and threat model of a contact tracing application.

Secure messaging tools are an integral part of modern society. To understand users’ security and privacy perceptions and requirements for secure group chat, we surveyed 996 respondents in the US and UK. Our results show that group chat presents important security and privacy challenges, some of which are not present in one-to-one chat. For example, users need to be able to manage and monitor group membership, establish trust for new group members, and filter content that they share in different chat contexts. We also find that respondents lack mechanisms for determining which tools are secure and instead rely on non-technical strategies for protecting their privacy—for example, self-filtering and carefully tracking group membership. To better understand how these results relate to existing tools, we conduct cognitive walkthroughs (a form of expert usability review) for five popular group chat tools. Our results demonstrate that while existing tools address some items identified in our surveys, this support is partial and is insufficient in many cases. As such, there is a need for improved group chat tools that better align with user perceptions and requirements. Based on these findings, we provide recommendations on improving the security and usability of secure group chat.

The needs of marginalised groups like migrant domestic workers (MDWs) are often ignored in digital privacy and security research. If considered, MDWs are treated as 'bystanders' or even as threats rather than as targets of surveillance and legitimate security subjects in their own right. Using participatory threat modelling (PTM) as a method of incorporating marginalised populations' experiences, we designed and conducted five workshops with MDWs (n=32) in the UK to identify threats to their privacy and security. We found that MDWs named government surveillance, scams and harassment, and employer monitoring (in this order) as the primary threats to their privacy and security. We also examined the methods MDWs used to stay safe online, such as configuring the privacy settings of their online accounts and creating on- and offline community support networks. Based on our findings, we developed and disseminated a digital privacy and security guide with links to further resources that MDWs can refer to. We conclude by arguing that security research must consider broader social structures like gendered work and racialised border policy that foster insecurity in the lives of MDWs. We also present the key lessons of our work, including considering data sharing from the perspective of stakeholders who do not own technology devices but are affected by them, and reflecting on how security research can stop enabling harmful forms of surveillance.

Smart home cameras raise privacy concerns in part because they frequently collect data not only about the primary users who deployed them but also other parties-who may be targets of intentional surveillance or incidental bystanders. Domestic employees working in smart homes must navigate a complex situation that blends privacy and social norms for homes, workplaces, and caregiving. This paper presents findings from 25 semi-structured interviews with domestic childcare workers in the U.S. about smart home cameras, focusing on how privacy considerations interact with the dynamics of their employer-employee relationships. We show how participants' views on camera data collection, and their desire and ability to set conditions on data use and sharing, were affected by power differentials and norms about who should control information flows in a given context. Participants' attitudes about employers' cameras often hinged on how employers used the data; whether participants viewed camera use as likely to reinforce negative tendencies in the employer-employee relationship; and how camera use and disclosure might reflect existing relationship tendencies. We also suggest technical and social interventions to mitigate the adverse effects of power imbalances on domestic employees' privacy and individual agency.

A cookie banner pops up when a user visits a website for the first time, requesting consent to the use of cookies and other trackers for a variety of purposes. Unlike prior work that has focused on evaluating the user interface (UI) design of cookie banners, this paper presents an in-depth analysis of what cookie banners say to users to get their consent. We took an interdisciplinary approach to determining what cookie banners should say. Following the legal requirements of the ePrivacy Directive (ePD) and the General Data Protection Regulation (GDPR), we manually annotated around 400 cookie banners presented on the most popular English-speaking websites visited by users residing in the EU. We focused on analyzing the purposes of cookie banners and how these purposes were expressed (e.g., any misleading or vague language, any use of jargon). We found that 89% of cookie banners violated applicable laws. In particular, 61% of banners violated the purpose specificity requirement by mentioning vague purposes, including "user experience enhancement". Further, 30% of banners used positive framing, breaching the freely given and informed consent requirements. Based on these findings, we provide recommendations that regulators can find useful. We also describe future research directions.

A cookie banner pops up when a user visits a website for the first time, requesting consent to the use of cookies and other trackers for a variety of purposes. Unlike prior work that has focused on evaluating the user interface (UI) design of cookie banners, this paper presents an in-depth analysis of what cookie banners say to users to get their consent. We took an interdisciplinary approach to determiningwhat cookie banners should say. Following the legal requirements of the ePrivacy Directive (ePD) and the General Data Protection Regulation (GDPR), we manually annotated around 400 cookie banners presented on the most popular English-speaking websites visited by users residing in the EU. We focused on analyzing the purposes of cookie banners and how these purposes were expressed (e.g., any misleading or vague language, any use of jargon). We found that 89% of cookie banners violated applicable laws. In particular, 61% of banners violated the purpose specificity requirement by mentioning vague purposes, including \emphuser experience enhancement ''. Further, 30% of banners used positive framing, breaching the freely given and informed consent requirements. Based on these findings, we provide recommendations that regulators can find useful. We also describe future research directions.

Although end-to-end encryption (E2EE) is more widely available than ever before, many users remain confused about its security properties. As a result, even users with access to E2EE tools turn to less secure alternatives for sending private information. To investigate these issues, we conducted a 357-participant online user study analyzing how explanations of security impact user perceptions. In a between-subjects design, we varied the terminology used to detail the security mechanism, whether encryption was on by default, and the prominence of security in an app-store-style description page. We collected participants' perceptions of the tool's utility for privacy, security against adversaries, and whether use of the tool would be seen as "paranoid.'' Compared to "secure,'' describing the tool as "encrypted'' or "military-grade encrypted'' increased perceptions that it was appropriate for privacy-sensitive tasks, whereas describing it more precisely as "end-to-end encrypted'' did not. However, "military-grade encrypted'' was also associated with a greater perception of tool use as paranoid. Overall, we find that --- compared to prior work from 2006 --- the social stigma associated with encrypted communication has largely disappeared.

The increasing use of smart home devices affects the privacy not only of device owners, but also of individuals who did not choose to deploy them, and may not even be aware of them. Some smart home devices and systems, especially those with cameras, can be used for remote surveillance of, for example, domestic employees. Domestic workers represent a special case of bystanders’ privacy, due to the blending of home, work, and care contexts, and employer–employee power differentials. To examine the experiences, perspectives, and privacy concerns of domestic workers, we begin with a case study of nannies and of parents who employ nannies. We conducted 26 interviews with nannies and 16 with parents. This paper describes the research agenda, motivation, and methodology for our study, along with preliminary findings.

Secure messaging tools are an integral part of modern society. While there is a significant body of secure messaging research generally, there is a lack of information regarding users’ security and privacy perceptions and requirements for secure group chat. To address this gap, we conducted a survey of 996 respondents in the US and UK. The results of our study show that group chat presents important security and privacy challenges, some of which are not present in one-to-one chat. For example, users need to be able to manage and monitor group membership, establish trust for new group members, and filter content that they share in different chat contexts. Similarly, we find that the sheer volume of notifications that occur in group chat makes it extremely likely that users ignore important security or privacy notifications. We also find that respondents lack mechanisms for determining which tools are secure and instead rely on non-technical strategies for protecting their privacy—for example, self-filtering what they post and carefully tracking group membership. Based on these findings, we provide recommendations on how to improve the security and usability of secure group chat.

Smart home devices are growing in popularity due to their functionality, convenience, and comfort. However, they are raising security and privacy concerns for users who may have very little technical ability. User experience (UX) focuses on improving user interactions, but little work has investigated how companies factor user experience into the security and privacy design of smart home devices as a means of addressing these concerns. To explore this in more detail, we designed and conducted six in-depth interviews with employees of a large smart home company in the United Kingdom. We analyzed the data using Grounded Theory, and found little evidence that UX is a consideration for the security design of these devices. Based on the results of our study, we proposed user-centered design guidelines and recommendations to improve data protection in smart homes.

Smart homes are under attack. Threats can harm both the security of these homes and the privacy of their inhabitants. As a result, in addition to delivering pleasing and aesthetic devices, smart home product designers need to factor security and privacy into the design of their devices. Further, the need for user-centered security and privacy design is particularly important for such an environment, given that inhabitants are demographically-diverse (e.g., age, gender, educational level) and have different skills and (dis)abilities. Prior work has explored different usable security and privacy solutions for smart homes; however, the applicability of user experience (UX) principles to security and privacy design is under-explored. In this paper, we present a qualitative study to explore the development of smart home cameras manufactured by three companies. We conduct semi-structured interviews with 20 designers and their collaborators, and analyze these interviews using Grounded Theory. We find that UX was seen as helpful by our participants in fostering innovation in the design of privacy solutions. However, UX was not used or considered in the design of security solutions due to an explicit need for established, tried-and-tested solutions (i.e., previous traditional security solutions that were seen as effective and reliable to fix certain design problems). Drawing from the findings of our study, we propose a model of UX factors influencing security and privacy design of smart home cameras. We also extract a set of recommendations to improve the security and privacy design of smart cameras. We finally outline several areas for future investigation.

With the popularity of tools like WhatsApp, end-to-end encryption (E2EE) is more widely available than ever before. Nonetheless, user perceptions lag behind. Users often do not understand E2EE’s security properties or believe them sufficient. Thus, even users with access to E2EE tools turn to less-secure alternatives for sending confidential information. To better understand these issues, we conducted a 357-participant online user study analyzing how explanations of encryption impact user perceptions. We showed participants an app-store-style description of a messaging tool, varying the terminology used, whether encryption was on by default, and the prominence of encryption. We collected perceptions of the tool’s security guarantees, appropriateness for privacy-focused use by whom and for what purpose, and perceptions of paranoia. Compared to “secure,” describing the tool as “encrypted” or “military-grade encrypted” increased perceptions it was appropriate for privacy-sensitive tasks, whereas describing it more precisely as “end-to-end encrypted” did not. Prior work had found an association between the use of encryption and being perceived as paranoid. We found this link minimized, but still partially applicable. Nonetheless, participants perceived encrypted tools as appropriate for general tasks.

The computer security community has advocated widespread adoption of secure communication tools to protect personal privacy. Several popular communication tools have adopted end-to-end encryption (e.g., WhatsApp, iMessage), or promoted security features as selling points (e.g., Telegram, Signal). However, previous studies have shown that users may not understand the security features of the tools they are using, and may not be using them correctly. In this paper, we present a study of Telegram using two complementary methods: (1) a labbased user study (11 novices and 11 Telegram users), and (2) a hybrid analytical approach combining cognitive walk-through and heuristic evaluation to analyse Telegram’s user interface. Participants who use Telegram feel secure because they feel they are using a secure tool, but in reality Telegram offers limited security benefits to most of its users. Most participants develop a habit of using the less secure default chat mode at all times. We also uncover several user interface design issues that impact security, including technical jargon, inconsistent use of terminology, and making some security features clear and others not. For instance, use of the end-to-end-encrypted Secret Chat mode requires both the sender and recipient be online at the same time, and Secret Chat does not support group conversations.

In light of recent revelations of mass state surveillance of phone and Internet communications, many solutions now claim to provide secure messaging. This includes both a broad range of new projects and several widely adopted applications that have added security features. However, despite the demand for better solutions, there is no clear winner in the race for widespread development and deployment of messaging products. Recently, the Electronic Frontier Foundation evaluated dozens of messaging tools based on security best practices, and publicized the results via the Secure Messaging Scorecard. Our goal is to expand the scorecard by evaluating messaging tools on a range of usefulness (utility and usability) attributes.