Location privacy preserving using semi-TTP server for LBS users

The advancements in location-aware devices such as smartphones, RFID chips, GPS devices and different positioning technologies has led to the growth and popularity of location based services. Location based Services offers various services to the user such as finding a route, reporting nearby friends, locating emergency centers, etc. User has to send a spatial query along with user location to the provider to obtain the service. Privacy of user in terms of user location and user information can be breached by the use of location based services. Most of the existing approaches use a fully-trusted third party which has some major drawbacks. In this paper, we developed a real world system which uses a semi-trusted third party which almost removes all the limitations of fully-trusted third party approach. This system provides location privacy in snapshot as well as continuous location based services. As smartphones have greater processing capacity, we have implemented an android smartphone application which performs all the cryptographic functions at user side and provide user a navigational map based system which can find desired point of interests along with the navigational routes. This system supports Reverse k-NN and k-NN queries and doesn't reveal location information to either the provider or semi-trusted third party. Experimental results shows that this system achieves better privacy for user location and user information in location based services.