Abstract:

Various location-based big data services not only provide users with convenience but also lead to privacy leakage risks.The local differential privacy model avoids the dependence on trusted third-party data collection platforms and enables users to process and protect sensitive information according to their personal needs.Therefore,it is more suitable for location privacy protection scenarios.In view of the complex encoding mechanism and low availability of the current local differential privacy location protection methods,a local differential privacy location protection method based on the Hilbert encoding is proposed.The user side performs random response perturbation on the Hilbert code of the grid where he is located according to the local differential privacy model,so as to realize the privacy protection of his original location.The server side collects a large number of users’ disturbed location codes and performs the Hilbert decoding,in order to determine the grid location of users and realize the statistical analysis of distribution density of users.Experiments on actual location datasets prove that the proposed method can provide a better location data availability and operational efficiency on the basis of realizing local differential privacy protection of users’ location.

Key words: location-based service, location privacy, local differential privacy, Hilbert encoding, random response