Smart speakers pose privacy risks to users and bystanders. We do not know how these risks are perceived depending on different factors, such as the potential privacy violators, the nature of the privacy violation, the different user groups, and culture. Understanding these perceptions is crucial to providing adequate privacy solutions and legislation. To this end, 1,768 participants from Germany and the UK answered our online-questionnaire about their perceptions of five different actors’ possibilities , intentions , and legal bases to commit five privacy violations: data access, data inference, overhearing conversations, secondary use, and passing data along. Participants expressed mild concerns about the main user but greater worry about manufacturers and the state. We observe growing concern among younger people, especially in the UK and that users who do not own the smart speaker are the least concerned group. Our approach can be used to better differentiate perceptions of concerns in other contexts.

Voice assistants, as provided by smart speakers, have become ubiquitous. Current authentication methods in these systems, however, rely on wake words, posing a risk due to the susceptibility to replay attacks. Additionally, user data stored on servers could expose sensitive information. This study suggests an approach to improve user authentication and profile management in smart speakers, reducing risks tied to external data processing and storage. We propose a two-fold solution for continuous user authentication and local user profiles. This approach prevents unauthorized access to sensitive data and grants users access to their local recordings. Our method differs from current practices in two ways: (1) It authenticates users based on complete voice commands, reducing the risk of replayed wake word attacks, and (2) it operates locally, avoiding the transfer of sensitive data to external servers. We offer a proof-of-concept with Alexa Voice Service (AVS) integration and a thorough evaluation using voice datasets and a study with 17 participants. We tested our approach under various conditions, including accents, background noise, and muffled speech. Legitimate users are identified with 93% precision, 95% recall, 94% F1-score, and 99% accuracy, while illegitimate users are recognized with 99% accuracy across these metrics.

A promising approach to further increase the safety of Vulnerable Road Users (VRUs) are cooperative collision avoidance systems. Cooperative collision avoidance systems actively integrate the VRUs in collision detection by using movement data from a VRU’s mobile device. While in recent years great attention was payed to solve technical challenges, e.g., regarding communication and sensor accuracy, little attention was payed to threats of privacy. However, the use and collection of such data poses certain privacy risks to the VRU. These privacy risks cannot be addressed by encryption alone. While some pseudonymisation approaches are used to protect the identity and location of VRUs, in this paper, we analyse to which extent the perturbation of movement data, specifically the speed data, can prevent the linkage of this data to a particular VRU, thus reducing the probability that this specific VRU can be identified. At the same time, we evaluate the trade-off between the probability of User Identification and the probability of collision detection. The evaluation is based on a standardised urban collision scenario between pedestrians and vehicles from the European New Car Assessment Programme. Our results show that privacy and "survival" are not mutually exclusive.

Even though technological advances changed and improved our daily life in various ways, the risks and dangers of extreme sport activities (ESAs) still persist and the progress of technology had little impact on them. Existing emergency rescue devices for ESAs still require manual activation and do not detect emergency situations autonomously. However, fusing the data feeds of simple sensors can easily enhance the functionalities of those devices and allow for the detection of emergency situations and subsequent rescue in the case of injuries. We identify the difficulties and challenges posed by ESAs, the role and potential value of information technology in such activities and example use cases and scenarios. We further present a prototype device for climbers that can detect potentially dangerous fall events.