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 trac reports, and location-based store nder. 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 o 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. The main idea is to employ a trusted third party, the Location Anonymizer, that expands the user location into a spatial region such...
Mohamed F. Mokbel