Internet of Things (IoT) devices have become increasingly important within the smart home domain, making the security of the devices a critical aspect. The majority of IoT devices are black-box systems running closed and pre-installed firmware. This raises concerns about the trustworthiness of these devices, especially considering that some of them are shipped with a microphone or a camera. Remote attestation aims at validating the trustworthiness of these devices by verifying the integrity of the software. However, users cannot validate whether the attestation has actually taken place and has not been manipulated by an attacker, raising the need for HCI research on trust and understandability. We conducted a qualitative study with 35 participants, investigating trust in the attestation process and whether this trust can be improved by additional explanations in the application. We developed an application that allows users to attest a smart speaker using their smartphone over an audio channel to identify the attested device and observe the attestation process. In order to observe the differences between the applications with and without explanations, we performed A/B testing. We discovered that trust increases when additional explanations of the technical process are provided, improving the understanding of the attestation process.

Farm Management Information Systems (FMIS) are an important core component of modern farming companies as they allow, e.g. to document activities, create fertilisation plans, and feed digital equipment with required data. Since the entire agricultural sector is an essential component of food production, high standards of resilience should be established in the involved companies. Accordingly, the used software should also be designed with high standards on reliability and crisis capability. Based on a literature review, we found that software for farmers with certain resilience needs is lacking. Thus, we designed and evaluated a new FMIS concept with the user-centred design method. By conducting focus groups (two rounds, total N = 57) in 2017 and 2019, we raised specific front-end and back-end requirements of farmers. Based on the requirements, we developed our concept for both front- and back-end in terms of a decentralised and offline-working FMIS. Through the evaluation with practitioners (N = 16) of the implemented concept, we derived findings and implications, highlighting the need for privacy, stability, and offline-capability, as well as the UI-requirement to be supportive, e.g. with easy to understand icons and terms.

In many applications and websites people use in their everyday life, their privacy and data are threatened, e.g., by script tracking during browsing. Although researchers and companies have developed privacy-enhancing technologies (PETs), they are often difficult to use for lay users. In this paper, we conducted a literature review to classify users into different extit{support personas} based on their privacy competence and privacy concern. With developers of PETs in mind, support personas were envisioned to facilitate the customization of software according to the support needs of different users. In order to demonstrate the usefulness of support personas and based on workshop sessions with 15 participants, we designed a browser extension that supports users with the issue of script tracking by providing different user interfaces for different support personas. The following qualitative evaluation with 31 participants showed that the developed UI elements worked as intended for the different support personas. Therefore, we conclude the concept of support personas is useful in the development process of usable applications that enhance the privacy of the users while also educating them and thus potentially increasing their privacy literacy.

In many scenarios, users have to communicate sensitive data with third parties such as doctors, lawyers, insurance companies, social workers, or online shops. Handing over personal data is necessary to use those services, but delegating tasks to increase efficiency still poses the risk that personal data might be leaked. To minimize this risk and further enhance the privacy of users, we propose an interaction concept that uses layered encryption of messages to provide a trade-off between privacy and usability. Users can choose which data is additionally encrypted in an inner layer, e.g. only for the eyes of their doctor, and which data is available in an outer (encrypted or unencrypted) layer for all staff members. Another benefit is the hiding of sensitive data from package inspection or crawling algorithms via emails, while less critical parts can still be processed by these systems via the partial access. To investigate this concept, we derive relevant use cases for form-based communication via email from a quantitative pre-study with 1011 participants, showing that general practitioners are the most suitable use case. We developed demonstrators for this use case and evaluated them in a qualitative study with 42 participants. Our results show that the possibility of minimizing the propagation of sensitive data through additional encryption is highly appreciated and the usage of form-based communication is a promising approach for digital transformation.

From the perspective of end-users, IoT devices behave like a black box: As long as they work as intended, users will not detect any compromise. Users have minimal control over the software. Hence, it is very likely that the user misses that illegal recordings and transmissions occur if a security camera or a smart speaker is hacked. In this paper, we present SCAtt-man, the first remote attestation scheme that is specifically designed with the user in mind. SCAtt-man deploys software-based attestation to check the integrity of remote devices, allowing users to verify the integrity of IoT devices with their smartphones. The key novelty of SCAtt-man resides in the utilization of user-observable side-channels such as light or sound in the attestation protocol. Our proof-of-concept implementation targets a smart speaker and an attestation protocol that is based on a data-over-sound protocol. Our evaluation demonstrates the effectiveness of \toolname against a variety of attacks and its usability based on a user study with 20 participants.

Business collaboration in the era of digital transformation requires the exchange of operational data. Since data are hardly controllable once they have been published or shared with others, it is highly important that users are clearly informed about who has access to which data and how certain settings can prevent the disclosure of sensitive data. However, giving end users more control over their data through increased transparency could also lead to information overload. This is particularly true in the field of agriculture, where tight schedules put pressure on employees of small enterprises. We conduct an empirical prestudy with 52 German farmers to investigate current data sharing scenarios. From these insights, we derive requirements and a concept for data sharing solutions providing data flow transparency for users. To investigate the behavior of users and the effects of transparent UI controls, we evaluate a prototype with 18 persons. Our evaluation shows that farmers demand flexible and secure tools that adjust to their workflows. Also, data should be stored and processed locally, granting farmers data sovereignty. Although the controls require additional effort, the evaluated transparent controls for data disclosure are easy to use and raise user awareness.

Abstract Technological progress can disrupt domains and change the way we work and collaborate. This paper presents a qualitative study with 52 German farmers that investigates the impact of the ongoing digitalization process in agriculture and discusses the implications for privacy research. As in other domains, the introduction of digital tools and services leads to the data itself becoming a resource. Sharing this data with products along the supply chain is favored by retailers and consumers, who benefit from traceability through transparency. However, transparency can pose a privacy risk. Having insight into the business data of others along the supply chain provides an advantage in terms of market position. This is particularly true in agriculture, where there is already a significant imbalance of power between actors. A multitude of small and medium-sized farming businesses are opposed by large upstream and downstream players that drive technological innovation. Further weakening the market position of farmers could lead to severe consequences for the entire sector. We found that on the one hand, privacy behaviors are affected by adoption of digitalization, and on the other hand, privacy itself influences adoption of digital tools. Our study sheds light on the emerging challenges for farmers and the role of privacy in the process of digitalization in agriculture.