A Grid-Based Cloaking Scheme for Continuous Queries in Distributed Systems

With the development of wireless communication technologies and popularity of smart phones, many people are using location-based services (LBSs). However, since users continuously request queries to LBS server by using their exact locations, their privacy information is always in danger. Because the existing techniques provide user´s privacy protection operating on centralized system, an anonymizer suffers from performance degradation and security problem. Therefore, a mechanism based on distributed system for users´ privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, we, in this paper, propose a grid-based cloaking scheme for continuous query processing in Distributed systems. The proposed scheme stores information and performs operations in distributed manner to create a cloaking area. In addition, the proposed scheme uses aggregate nodes to prevent query issuers´ bottleneck. Through performance analysis, we show that our cloaking scheme outperforms the existing centralized cloaking schemes in terms of service time.