Abstract: With the broad range of application of location detected device such as mobile phone, GPS and RFID etc, the researchers have paid more and more attention to the locationbased services (LBS). Though LBS brings convenience to us, it also rises up the risk of location privacy leakages. The existing LBS systems transform the users’ locaiton into a rectangle or circle cloaking region by location generalization. Then, the users’ location can be hidden in the cloaking region to achieve the purpose of protecting the users’ locaiton privacy. However, in practical applications, the cloaking region may be related to the actual landform for the users’ location, it may not be a rectangle or circle region. In fact, a rectangle or circle region even may result in the increase of invalid region and reduce the location information accuracy. In this paper, based on the shortcoming of existing systems, we design and implement a new system in which the user can define the polygonal cloaking region based on actual landform. At the meantime, the system can provide a double protection for the users’ location privacy. The system performance tests show the effectiveness of the propsed system.

Key words: locationbased services, locationbased privacy protection, polygonal cloaking region