Towards an Open Source Toolkit for Ubiquitous Device Authentication

Most authentication protocols designed for ubiquitous computing environments try to solve the problem of intuitive, scalable, secure authentication of wireless communication. Due to the diversity of requirements, protocols tend to be implemented within specific research prototypes and can not be used easily in other applications. We propose to develop a common toolkit for ubiquitous device authentication to foster wide usability of research results. This paper outlines design goals and presents a first, freely available implementation

Towards an Open Source Toolkit for Ubiquitous Device Authentication

Most authentication protocols designed for ubiquitous computing environments try to solve the problem of intuitive, scalable, secure authentication of wireless communication. Due to the diversity of requirements, protocols tend to be implemented within specific research prototypes and can not be used easily in other applications. We propose to develop a common toolkit for ubiquitous device authentication to foster wide usability of research results. This paper outlines design goals and presents a first, freely available implementation. 1

Designing for Cross-Device Interactions

Driven by technological advancements, we now own and operate an ever-growing number of digital devices, leading to an increased amount of digital data we produce, use, and maintain. However, while there is a substantial increase in computing power and availability of devices and data, many tasks we conduct with our devices are not well connected across multiple devices. We conduct our tasks sequentially instead of in parallel, while collaborative work across multiple devices is cumbersome to set up or simply not possible. To address these limitations, this thesis is concerned with cross-device computing. In particular it aims to conceptualise, prototype, and study interactions in cross-device computing. This thesis contributes to the field of Human-Computer Interaction (HCI)—and more specifically to the area of cross-device computing—in three ways: first, this work conceptualises previous work through a taxonomy of cross-device computing resulting in an in-depth understanding of the field, that identifies underexplored research areas, enabling the transfer of key insights into the design of interaction techniques. Second, three case studies were conducted that show how cross-device interactions can support curation work as well as augment users’ existing devices for individual and collaborative work. These case studies incorporate novel interaction techniques for supporting cross-device work. Third, through studying cross-device interactions and group collaboration, this thesis provides insights into how researchers can understand and evaluate multi- and cross-device interactions for individual and collaborative work. We provide a visualization and querying tool that facilitates interaction analysis of spatial measures and video recordings to facilitate such evaluations of cross-device work. Overall, the work in this thesis advances the field of cross-device computing with its taxonomy guiding research directions, novel interaction techniques and case studies demonstrating cross-device interactions for curation, and insights into and tools for effective evaluation of cross-device systems

Integrating Usability Models into Pervasive Application Development

This thesis describes novel processes in two important areas of human-computer interaction (HCI) and demonstrates ways to combine these in appropriate ways. First, prototyping plays an essential role in the development of complex applications. This is especially true if a user-centred design process is followed. We describe and compare a set of existing toolkits and frameworks that support the development of prototypes in the area of pervasive computing. Based on these observations, we introduce the EIToolkit that allows the quick generation of mobile and pervasive applications, and approaches many issues found in previous works. Its application and use is demonstrated in several projects that base on the architecture and an implementation of the toolkit. Second, we present novel results and extensions in user modelling, specifically for predicting time to completion of tasks. We extended established concepts such as the Keystroke-Level Model to novel types of interaction with mobile devices, e.g. using optical markers and gestures. The design, creation, as well as a validation of this model are presented in some detail in order to show its use and usefulness for making usability predictions. The third part is concerned with the combination of both concepts, i.e. how to integrate user models into the design process of pervasive applications. We first examine current ways of developing and show generic approaches to this problem. This leads to a concrete implementation of such a solution. An innovative integrated development environment is provided that allows for quickly developing mobile applications, supports the automatic generation of user models, and helps in applying these models early in the design process. This can considerably ease the process of model creation and can replace some types of costly user studies.Diese Dissertation beschreibt neuartige Verfahren in zwei wichtigen Bereichen der Mensch-Maschine-Kommunikation und erläutert Wege, diese geeignet zu verknüpfen. Zum einen spielt die Entwicklung von Prototypen insbesondere bei der Verwendung von benutzerzentrierten Entwicklungsverfahren eine besondere Rolle. Es werden daher auf der einen Seite eine ganze Reihe vorhandener Arbeiten vorgestellt und verglichen, die die Entwicklung prototypischer Anwendungen speziell im Bereich des Pervasive Computing unterstützen. Ein eigener Satz an Werkzeugen und Komponenten wird präsentiert, der viele der herausgearbeiteten Nachteile und Probleme solcher existierender Projekte aufgreift und entsprechende Lösungen anbietet. Mehrere Beispiele und eigene Arbeiten werden beschrieben, die auf dieser Architektur basieren und entwickelt wurden. Auf der anderen Seite werden neue Forschungsergebnisse präsentiert, die Erweiterungen von Methoden in der Benutzermodellierung speziell im Bereich der Abschätzung von Interaktionszeiten beinhalten. Mit diesen in der Dissertation entwickelten Erweiterungen können etablierte Konzepte wie das Keystroke-Level Model auf aktuelle und neuartige Interaktionsmöglichkeiten mit mobilen Geräten angewandt werden. Der Entwurf, das Erstellen sowie eine Validierung der Ergebnisse dieser Erweiterungen werden detailliert dargestellt. Ein dritter Teil beschäftigt sich mit Möglichkeiten die beiden beschriebenen Konzepte, zum einen Prototypenentwicklung im Pervasive Computing und zum anderen Benutzermodellierung, geeignet zu kombinieren. Vorhandene Ansätze werden untersucht und generische Integrationsmöglichkeiten beschrieben. Dies führt zu konkreten Implementierungen solcher Lösungen zur Integration in vorhandene Umgebungen, als auch in Form einer eigenen Applikation spezialisiert auf die Entwicklung von Programmen für mobile Geräte. Sie erlaubt das schnelle Erstellen von Prototypen, unterstützt das automatische Erstellen spezialisierter Benutzermodelle und ermöglicht den Einsatz dieser Modelle früh im Entwicklungsprozess. Dies erleichtert die Anwendung solcher Modelle und kann Aufwand und Kosten für entsprechende Benutzerstudien einsparen