Enhancing User Location Privacy through Grid System based Location Sharing using Modified Caesar Cipher Method

Abstract

Advancement in the field of mobile computing has led to the increased usage of Location based services that enables the mobile users to retrieve POI (Points of Interests) such as ATM (Automated Teller Machine) centers, Hospitals etc. in accordance to their location. The mobile user is required to send his location data in the form of GPS (Global Positioning System) coordinates as input to the Service Provider. However potential privacy loss for the user can happen due to the disclosure of his location data. Thus disclosure of user location paves way for mendacious service providers to develop user movement profile. Hence a major enhancement compared to existing solutions is provided by using a symmetric key cryptography algorithm together with modified Caesar cipher method, which employs bit manipulation method and modular reduction. That includes a two stage approach, where the first step is based on symmetric key transfer and the encrypted query transfer containing user's location in the form of grid and POI. The user is required to enter the POI details and the corresponding area which is sent to the service provider in encrypted form. And the second step involves symmetric key based retrieval of the point of interests from the service provider. The point of interest requested by the user is extracted from the public grid of the service provider and it is returned to the user in the encrypted form. The user decrypts the list of points of interests which can be then viewed on a map. A secure solution is provided for both parties which includes the user who is in need of the query location and the service provider. An efficient and practical solution is provided by incorporating a real cloud location and android application.