Touchalytics: On the Applicability of Touchscreen Input as a Behavioral Biometric for Continuous Authentication

We investigate whether a classifier can continuously authenticate users based on the way they interact with the touchscreen of a smart phone. We propose a set of 30 behavioral touch features that can be extracted from raw touchscreen logs and demonstrate that different users populate distinct subspaces of this feature space. In a systematic experiment designed to test how this behavioral pattern exhibits consistency over time, we collected touch data from users interacting with a smart phone using basic navigation maneuvers, i.e., up-down and left-right scrolling. We propose a classification framework that learns the touch behavior of a user during an enrollment phase and is able to accept or reject the current user by monitoring interaction with the touch screen. The classifier achieves a median equal error rate of 0% for intra-session authentication, 2%-3% for inter-session authentication and below 4% when the authentication test was carried out one week after the enrollment phase. While our experimental findings disqualify this method as a standalone authentication mechanism for long-term authentication, it could be implemented as a means to extend screen-lock time or as a part of a multi-modal biometric authentication system.Comment: to appear at IEEE Transactions on Information Forensics & Security; Download data from http://www.mariofrank.net/touchalytics

The Role of Eye Gaze in Security and Privacy Applications: Survey and Future HCI Research Directions

For the past 20 years, researchers have investigated the use of eye tracking in security applications. We present a holistic view on gaze-based security applications. In particular, we canvassed the literature and classify the utility of gaze in security applications into a) authentication, b) privacy protection, and c) gaze monitoring during security critical tasks. This allows us to chart several research directions, most importantly 1) conducting field studies of implicit and explicit gaze-based authentication due to recent advances in eye tracking, 2) research on gaze-based privacy protection and gaze monitoring in security critical tasks which are under-investigated yet very promising areas, and 3) understanding the privacy implications of pervasive eye tracking. We discuss the most promising opportunities and most pressing challenges of eye tracking for security that will shape research in gaze-based security applications for the next decade

Collecting Links between Entities Ranked by Human Association Strengths

In recent years, the ongoing adoption of Semantic Web technologies has lead to a large amount of Linked Data that has been generated. While in the early days of the Semantic Web we were fighting data scarcity, nowadays we suffer from an overflow of information. In many situations we want to restrict the amount of facts which is shown to an end-user or passed on to another system to just the most important ones. In this paper we propose to rank facts in accordance to human association strengths between concepts. In order to collect a ground truth we developed a Family Feud like web-game called “Knowledge Test Game”. Given a Linked Data entity it collects other associated Linked Data entities from its players. We explain the game’s concept, its suggestion box which maps the players’ text input back to Linked Data entities and include a detailed evaluation of the game showing promising results. The collected data is published and can be used to evaluate algorithms which rank facts

BetterRelations: collecting association strengths for linked data triples with a game

The simulation of human thinking is one of the long term goals of the Artificial Intelligence community. In recent years, the adoption of Semantic Web technologies and the ongoing sharing of Linked Data has generated one of the world’s largest knowledge bases, bringing us closer to this dream than ever. Nevertheless, while associations in the human memory have different strengths, such explicit association strengths (edge weights) are missing in Linked Data. Hence, finding good heuristics which can estimate human-like association strengths for Linked Data facts (triples) is of major interest to us. In order to evaluate existing approaches with respect to human-like association strengths, we need a collection of such explicit edge weights for Linked Data triples. In this chapter we first provide an overview of existing approaches to rate Linked Data triples which could be valuable candidates for good heuristics. We then present a web-game prototype which can help with the collection of a ground truth of edge weights for triples. We explain the game’s concept, summarize Linked Data related implementation aspects, and include a detailed evaluation of the game