H-Star: Hilbert-order Based Star Network Expansion Cloaking Algorithm in Road Networks

The proliferations of position identifying devices become increasing privacy threat in location-based services (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 a XStar framework to hide the query issuer and provide protection from attack resilience. However, it incurs low anonymization success rate and computation cost is quite high. To address these issues, we propose 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. Through comprehensive experimental evaluations, we show the effectiveness of our algorithm in the field of spatial cloaking.