DEFINITION
Spatial cloaking is a technique to blur a user’s exact location into a spatial region in order to preserve her location privacy. The blurred spatial region must satisfy the user’s specified privacy requirement. The most widely used privacy requirements are k-anonymity and minimum spatial area. The k-anonymity requirement guarantees that a user location is indistinguishable among k users. On the other hand, the minimum spatial area requirement guarantees that a user exact location must be blurred into a spatial region with an area of at least A, such that the probability of the user being located in any point within the spatial region is A1 . A user location must be
blurred by a spatial cloaking algorithm either on the client side or a trusted third-party before it is submitted to a location-based database server.