Virtual Walls: Protecting Digital Privacy in Pervasive Environments


Apu Kapadia, Tristan Henderson, Jeffrey Fielding, and David Kotz. Virtual Walls: Protecting Digital Privacy in Pervasive Environments. Proceedings of the International Conference on Pervasive Computing (Pervasive), volume 4480 in Lecture Notes in Computer Science, pages 162–179. Springer-Verlag, May 2007. doi:10.1007/978-3-540-72037-9_10. ©Copyright Springer-Verlag. Honorable Mention for Best Paper.


As pervasive environments become more commonplace, the privacy of users is placed at an increased risk. The numerous and diverse sensors in these environments can record contextual information about users, leading to users unwittingly leaving “digital footprints.” Users must therefore be allowed to control how their digital footprints are reported to third parties. While a significant amount of prior work has focused on location privacy, location is only one specific type of footprint, and we expect most users to be incapable of specifying fine-grained policies for a multitude of footprints. In this paper we present a policy language based on the metaphor of physical walls, and posit that users will find this to be an intuitive way to control access to their digital footprints. For example, users understand the physical privacy implications of conducting a meeting in a room enclosed by physical walls. By allowing users to deploy “virtual walls,” they can control the privacy of their digital footprints much in the same way they control their privacy in the physical world. We present a policy framework and model for virtual walls with three levels of transparency that correspond to intuitive levels of privacy. We also describe the results of a user study (N = 23) that indicates that our model is easy to understand and use.

Citable with [BibTeX]

Projects: [metrosense]

Keywords: [privacy] [sensors]

Available from the publisher: [DOI]

Available from the author: [bib] [pdf]
This pdf is the authors' near-final copy; the publisher does not allow us to post the final pdf.

[Kotz research]