Differentially Private Location Preservation with Staircase Mechanism Under Temporal Correlations

Location-Based Service (LBS) is one of basic services in collaborative applications. However, LBS applications may disclose user’s location privacy, which receives considerable concerns. Many methods have been proposed to protect privacy in LBS. Planar Isotropic Mechanism (PIM) is a typical location privacy preservation method in the scenario of continuous location data release. However, the method is complicated, since it requires two convex hull transformations and one isotropic position transform. To solve the problem, we propose a Staircase Mechanism (SM) based location privacy preservation method for the scenario of continuous location data release. The proposed method replaces PIM with SM, whose implementation is simple and efficient. Furthermore, SM can achieve the same privacy budget with less noise addition, so it can maintain higher quality of services in LBS. Comprehensive experiments conducted on real location data demonstrate that the proposed method is efficient and can maintain high data utility compared with the method based on PIM.