User Location Anonymization Method for Wide Distribution of Dummies.

Advances in GPS (global positioning system) technologies have led to a variety of services utilizing the user's location becoming available. Since location information may reveal private information, preserving location privacy has become a significant issue. To preserve this privacy, we have proposed a user location anonymization method that generates dummies on the basis of the user's trajectory with pauses in movement. However, the previous work does not sufficiently satisfy users' requirements for location privacy because the locations of the generated dummies tended to gather in a small area as time passed. In this paper, we propose a user location anonymization method that always keeps dummies' locations in an area wide enough to anonymize the user's location. Our method periodically distributes dummies by moving them to an area where there were fewer users and dummies. We simulated the user's movement on a real map and verified that the proposed method was more effective than the previous one. © 2013 Springer-Verlag.