Hilbert-order based spatial cloaking algorithm in road network

Location-based services (LBSs) are currently some of the fastest growing information technology industries. User privacy in LBSs has attracted great interest in the research community. However, the proliferation of position identifying devices has become an increasing privacy threat for users in LBSs. It is very difficult to avoid the privacy threat of a user in processing his/her request because the user has to submit his/her exact location with a query to the LBS. To protect privacy in road networks, the existing method employs an X-Star framework to hide the query issuer and provide protection from attack resilience. However, it incurs low anonymization success rate and high computation cost. To solve the problems, we propose a Hilbert-order-based star network expansion cloaking algorithm (H-Star). Our H-Star guarantees k-anonymity under the strict reciprocity condition and increases anonymization success rate by reducing computation overhead. We also propose k-nearest neighbor and range query processing algorithms based on the anonymized region. Through comprehensive experimental analysis, we show the effectiveness of our algorithms in the field of spatial cloaking.