Digital privacy behind virtual walls

Ubiquitous computing was the only subject discussed at the 5th International Conference on Pervasive Computing held in Toronto, Ontario, Canada, on May 13-16, 2007. As reports the National Post, 'in the future, everything will be a computer.' As ultra small computers can now embedded in virtually everything, pervasive computing applications will have a double impact on our lives. On one side, they'll be friendly, because almost 'invisible.' On the other hand, they'll reduce our personal privacy. While the article mentioned above describes a whole range of pervasive applications, this post just looks at one which can gives us back some privacy: virtual walls.

Ubiquitous computing was the only subject discussed at the 5th International Conference on Pervasive Computing held in Toronto, Ontario, Canada, on May 13-16, 2007. As reports the National Post, in the future, everything will be a computer. As ultra small computers can now embedded in virtually everything, pervasive computing applications will have a double impact on our lives. On one side, they'll be friendly, because almost 'invisible.' On the other hand, they'll reduce our personal privacy. While the article mentioned above describes a whole range of pervasive applications, this post just looks at one which can gives us back some privacy: virtual walls.

Staying private behind virtual wallsThe two images on the left illustrate this concept of virtual walls. Even in a private meeting room, invisible sensors can transmit information about you. Apu Kapadia, a post-doctoral research fellow at Dartmouth College in New Hampshire, is concerned by this problem, and explains "that the 'digital footprints' we are leaving, will only grow larger in the future."

On the top image, "Alice and Bob are aware of their physical privacy within the meeting room, but sensors are leaking personal footprints to the pervasive environment." But in the bottom image, "Alice and Bob deploy a translucent virtual wall to prevent unwanted disclosure of personal footprints." (Credit: Apu Kapadia and colleagues, Dartmouth College, US)

Of course, other technologies threatening our privacy in a way or another were presented during Pervasive 2007, the 5th International Conference on Pervasive Computing held in Toronto, Ontario, Canada, on May 13-16, 2007. And by the way, the proceedings of this conference are available from Springer-Verlag in the series Lecture Notes in Computer Science (LNCS) for 55,64 €.

Here is another example given by the National Post article.

Witness the double-edged possibility opened up by the map Darren Leigh of Mitsubishi Electric Research Laboratories has on display. It shows his lab facilities in Cambridge, Mass., with flashing lights denoting people as they move down the halls and dart in and out of rooms of the facility. Sensors stuck around building, small enough to fit in the palm of his hand, tracked people as they walked.
While Mr. Leigh highlighted the positive real-world applications for such technology, including searching for survivors after an earthquake, he admits it raises troubling privacy issues. Police and government surveillance could go beyond wiretapping to body-tapping; big business could track a person's spending and shopping habits; on the criminal front, the sensors could enable better stalking, kidnapping, and theft now that our every location is broadcast to the world.

Leigh is not alone. Adam Greenfield, the author of the book "Everyware: The Dawning Age of Ubiquitous Computing" (Amazon link), and who delivered a keynote address at Pervasive 2007, "believes that the only bastion for privacy in this technological future may be in the home: 'I think in public space, the battle is already over, and the forces of privacy have lost.'"

Now, let's return to the research work done by Kapadia and his colleagues at Dartmouth College. The paper they presented at the conference was entitled "Virtual Walls: Protecting Digital Privacy in Pervasive Environments" (PDF format, 18 pages, 1.12 MB). Here is an excerpt from the introduction.

As pervasive environments become more commonplace, the privacy of users is placed at increased risk. The numerous and diverse sensors in these environments can record users' contextual information, leading to users unwittingly leaving "digital footprints." Users must thus 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 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 abstraction to be an intuitive way to control access to their digital footprints. For example, users understand the privacy implications of 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.

For more information about this research work, you also should read a previous paper, "People-Centric Urban Sensing: Security Challenges for the New Paradigm" (PDF format, 19 pages, 154 KB, February 2007).

Sources: Mark Medley, National Post, Canada, May 19, 2007; and various websites

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