http://www.scientificamerican.com/article.cfm?articleID=000D5C44-6723-1D59-9... The technique, developed by Mark D. Corner and Brian D. Noble of the University of Michigan College of Engineering, is dubbed Zero-Interaction Authentication, or ZIA. It requires two pieces of hardware: the laptop and a so-called authentication token that communicates with the computer via a wireless link. As long as the token, which can be built into a wearable accessory such as a watch, is within range of the computer, the computer's systems function normally. But once the computer is separated from the token, its files automatically become encrypted. "When a user walks away from his laptop to get a cup of coffee, it will sense that he is leaving and begin securing the computer,"