University of Minho
The wide spread of location-based services results in a strong market for location-detection devices (e.g., GPS-like devices, RFIDs, handheld devices, and cellular phones). Examples of location-based services include location-aware emergency service, location-based advertisement, live traffic reports, and location-based store under. However, location-detection devices pose a major privacy threat on its users where it transmits private information (i.e., the location) to the server who may be untrustworthy. The existing model of location-based applications trades service with privacy where if a user wants to keep her private location information, she has to turn off her location-detection device, i.e., unsubscribe from the service. This paper tackles this model in a way that protects the user privacy while keeping the functionality of location-based services.