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.