Coordinate transformation - a solution for the privacy problem of location based services?

Protecting location information of mobile users in location based services (LBS) is a very important but quite difficult and still largely unsolved problem. Location information has to be protected against unauthorized access not only from users but also from service providers storing and processing the location data, without restricting the functionality of the system. This paper discusses why existing privacy enhancing techniques are insufficient to solve this problem and proposes a new approach basing on coordinate transformations. It shows how location information can be rendered illegible in such a way that it is still possible to perform processing operations required by LBS