Combating shoulder-surfing: a hidden button gesture based scheme

This project describes an authentication technique that is shoulder-surfing resistant. Shoulder surfing is an attack in which an attacker can get access to private information by observing the user’s interaction with a terminal, or by using recording tools to record the user interaction and study the obtained data, with the objective of obtaining unauthorized access to a target user’s personal information. The technique described here relies on gestural analysis coupled with a secondary channel of authentication that uses button pressing. The thesis presents and evaluates multiple alternative algorithms for gesture analysis, and furthermore assesses the effectiveness of the technique.

Remote presence: supporting deictic gestures through a handheld multi-touch device

This thesis argues on the possibility of supporting deictic gestures through handheld multi-touch devices in remote presentation scenarios. In [1], Clark distinguishes indicative techniques of placing-for and directing-to, where placing-for refers to placing a referent into the addressee’s attention, and directing-to refers to directing the addressee’s attention towards a referent. Keynote, PowerPoint, FuzeMeeting and others support placing-for efficiently with slide transitions, and animations, but support limited to none directing-to. The traditional “pointing feature” present in some presentation tools comes as a virtual laser pointer or mouse cursor. [12, 13] have shown that the mouse cursor and laser pointer offer very little informational expressiveness and do not do justice to human communicative gestures. In this project, a prototype application was implemented for the iPad in order to explore, develop, and test the concept of pointing in remote presentations. The prototype offers visualizing and navigating the slides as well as “pointing” and zooming. To further investigate the problem and possible solutions, a theoretical framework was designed representing the relationships between the presenter’s intention and gesture and the resulting visual effect (cursor) that enables the audience members to interpret the meaning of the effect and the presenter’s intention. Two studies were performed to investigate people’s appreciation of different ways of presenting remotely. An initial qualitative study was performed at The Hague, followed by an online quantitative user experiment. The results indicate that subjects found pointing to be helpful in understanding and concentrating, while the detached video feed of the presenter was considered to be distracting. The positive qualities of having the video feed were the emotion and social presence that it adds to the presentations. For a number of subjects, pointing displayed some of the same social and personal qualities [2] that video affords, while less intensified. The combination of pointing and video proved to be successful with 10-out-of-19 subjects scoring it the highest while pointing example came at a close 8-out-of-19. Video was the least preferred with only one subject preferring it. We suggest that the research performed here could provide a basis for future research and possibly be applied in a variety of distributed collaborative settings.