A Collaboration-Based Scheme for Location-Based Services with Incentive Mechanism

With the proliferation of communication networks and mobile devices, Location-based services (LBSs) have brought a variety of applications and conveniences in our daily life. While LBSs greatly benefit users, they bring significant threats to users' privacy. To enhance privacy protection for LBSs, a well-used technique is to establish a collaborative group which helps each other to avoid privacy leakage. Due to extremely unbalanced system overheads for group members, many users are short of intrinsic motivations to join the collaborative group in existing schemes. To address this problem, we propose a collaborative group system combined with dummy selection technique, termed CGS-DS, which not only limits mobile users consuming significant resources in collaborative group through the hop distance, but also inspires them to generate and cache the service data of dummies for other group members. Our CGS-DS uses a threshold assignment module to generate a suitable threshold of the hop distance. While the hop distance reaches the specified threshold, the user executes the dummy-cache module to generate some dummy queries and cache the service data for other members to use. Security analysis and evaluation results indicate its effectiveness and efficiency.