Abstract Two-factor authentication (2FA) is an effective measure to safeguard against password attacks (e.g., guessing, credential stuffing). However, many existing 2FA methods are neither user-friendly nor protect adequately against phishing, particularly real-time (person-in-the-middle) attacks. We introduce BlueTOTP , a novel approach that leverages Bluetooth to automatically transmit time-based one-time passwords (TOTP) and verify the requesting domain before issuing the second factor. By reducing manual interactions and ensuring domain legitimacy, BlueTOTP streamlines the authentication process and mitigates phishing risks. We present the design and implementation of BlueTOTP, followed by an evaluation of its usability and performance. BlueTOTP not only improves the user experience during authentication but also significantly reduces the overall time required to complete 2FA authentication.

Delivery robots are an emerging technology that promise benefits (reducing reliance on human-driven delivery vehicles and minimizing the impact of local traffic conditions). One limitation of such robots is their restricted range. A potential solution is to integrate these robots into existing public transport (PT) systems. One underexplored direction is extending their mobility through PT like buses. This scenario introduces distinct human–robot interaction (HRI) challenges: close physical proximity, shifting attention, implicit social norms, and multiple stakeholders occupying the same confined space.

This paper presents a method and case study to visualize the urban stock of materials and its availability for use in building future cities. Re-using material from existing buildings for new buildings can be seen as a source for construction materials in times of depleting natural resources. The authors explain the concept of "urban mining" and the challenges, such as "How much resources are available in a city? Today? In the near future?" We explore what data are needed to answer the questions, and then discuss how to best visualize the data in an effective and intuitive way. We apply the concept to an exemplary real-world district in Singapore that is in transformation. Then, we discuss features of a visual tool prototype and explain the thinking behind the design, e.g., how the spatial and temporal dimensions can be presented. Lastly, we conclude the paper with an outlook of future challenges. The paper presents a multi-disciplinary approach with researchers from computer science, architecture, graphic design and material science, and contributes to the discussion of how to visualize knowledge and plan sustainable future cities.