Ultrasound and near-ultrasound acoustic frequencies offer non-intrusive and low-overhead mediums for data transmission protocols. These protocols and the technologies built upon them are becoming more prevalent, yet their security remains largely unexplored. We present the first systematization of ultrasound and near-ultrasound enabled applications, developing a unified threat model to address their security. Our analysis reveals misguided assumptions, missing protections, and the need for standardization. Through our taxonomy, we highlight key insights, future research directions, and propose a framework for securing these protocols.

Security courses often focus on individual attacks and defenses, and lack practical experience with secure system design. Consequently, such courses rarely address the societal implications of security breaches. We propose an inductive teaching approach to address these challenges in teaching security engineering. To this end, we design a course that focuses on electronic voting (e-voting) as a practical application of security engineering. Our course integrates relevant technical content through experiential learning, adversarial thinking skills through a group project, and societal factors with a student debate. Our approach has seen success in engaging students in both distance-learning and in-person teaching while preparing them for real-world security challenges.

A key feature of smart home devices is monitoring the environment and recording data. These devices provide security via motion-detection video alerts, cost-savings via thermostat usage history, and peace of mind via functions like auto-locking doors or water leak detectors. At the same time, the sharing of this information in interpersonal relationships---though necessary---is currently accomplished on an all-or-nothing basis. This can easily lead to oversharing in a multi-user environment. Although prior work has studied people's perceptions of information sharing with vendors or ISPs, the sharing of household data among users who interact personally is less well understood. Interpersonal situations make data sharing much more context-based and, thus, more complicated. In this paper, we use themes from the theory of contextual integrity in an online survey (n=1,992) to study how people perceive data sharing with others in smart homes and inform future designs and research. Our results show that data recipients in a smart home can be reduced to three major groups, and data types matter more than device types. We also found that the types of access control desired by users can vary from scenario to scenario. Depending on whom they are sharing data with and about what data, participants expressed varying levels of comfort when presented with different types of access control (e.g., explicit approval versus time-limited access). Taken together, this provides strong evidence that a more dynamic access control system is needed, and we can design it in a more usable way.