AFCEA Exhibition 2022

7 April 2022

The Usable Security and Privacy Group, led by Prof. Alt, presents two interesting research projects at this year's AFCEA Exhibition in Bonn.

HotFoot

Foot biometric has both the physiological and behavioural characteristics.Despite its great potential, foot biometric remains underexplored. One reasonbehind this is, it involves removal of shoes and socks. As thermal camerasbecome ubiquitous, we foresee a new form of capturing footprints. Thermalcameras allow capturing thermal footprints, where heat traces, resulting fromstepping, can be used to reconstruct the footprint to identify users while usersstill have the shoes or socks on. We propose a novel method that combinesthermal and visible features of the foot to seamlessly and unobtrusively identifyusers. We collected a dataset of users’ steps with shoes and socks in a userstudy (N=20). Using a Logistic Regression on extracted features, our proposedsystem achieves an AUC score up to 0.98 for shoes footprints and 0.92 forsocks footprints. Our findings not only demonstrate the potential of thermalimaging for unobtrusive user identification, but also pave the way for novelapplications for usable security and seamless identification.

PriKey

The increasing number of smart devices installed in our homes poses privacy risks for inhabitants and visitors. However, individualsface difficulties counteracting privacy intrusions due to missing controls, incorrect mental models, and limitations in their level ofexpertise. We present PriKey, a concept for device-independent and easy-to-use tangible smart home privacy mechanisms. PriKey isthe key to privacy protection: it supports users in taking control over their privacy through meaningful, tangible interactions. Usinga Wizard-of-Oz prototype, we explored users’ perceptions regarding PriKey (𝑁 = 16). We then compared PriKey to an equivalentsmartphone app (𝑁 = 32), focusing on visitors. Participants perceived PriKey as engaging, intuitive, and benevolent. Their privacyconsiderations were based on personal and contextual factors.Our results indicate that tangible privacy is a noteworthy approach for future smart home privacy mechanisms.