Some Techniques for Privacy in Ubicomp and Context-Aware Applications

The emergence of ubiquitous computing opens up radical new possibilities for acquiring and sharing information. But the privacy risks from widespread use of location or environmental sensing are unacceptable to many users. This paper describes a new methodology that provides much finer control over information exchange: only the information needed for the collaboration is shared, everything else is protected, and protection is provably strong. This allows us to explore collaborative applications in ubicomp settings that are exciting but which would be difficult or impossible without the techniques we propose. Specifically, we are developing an ubiquitous information-sharing service. This service provides recommendations for places, events, and many other items and services, using recommendations from a community of users. The recommendations are both explicit from user ratings, and implicit by using log data to infer a user’s presence or use of a service. The services is intended for location-enabled devices like cell phones and PDAs with