Biblio

Geo-social applications deal with constantly sharing user's current geographic information in terms of location (Latitude and Longitude). Such application can be used by many people to get information about their surrounding with the help of their friend's locations and their recommendations. But without any privacy protection, these systems can be easily misused by tracking the users. We are proposing Error Based Transformation (ERB) approach for location transformation which provides significantly improved location privacy without adding uncertainty in to query results or relying on strong assumptions about server security. The key insight is to apply secure user-specific, distance-preserving coordinate transformations to all location data shared with the server. Only the friends of a user can get exact co-ordinates by applying inverse transformation with secret key shared with them. Servers can evaluate all location queries correctly on transformed data. ERB privacy mechanism guarantee that servers are unable to see or infer actual location data from the transformed data. ERB privacy mechanism is successful against a powerful adversary model where prototype measurements used to show that it provides with very little performance overhead making it suitable for today's mobile device.