A Combined Approach of Heat Map Confusion and Local Differential Privacy for the Anonymization of Mobility Data

Mobility data plays a crucial role in modern location-based services (LBSs), yet it poses significant privacy risks, as it can reveal highly sensitive information such as home locations and behavioral patterns. This paper focuses on the anonymization of mobility data by obfuscating mobility heat maps and combining this with a local differential privacy method, which generates synthetic mobility traces. Using the San Francisco Cabspotting dataset, we compare the effectiveness of the combined approach against reidentification attacks. Our results show that mobility traces treated with both a heat map obfuscation and local differential privacy are less likely to be reidentified than those anonymized solely with Heat Map Confusion. This two-tiered anonymization process balances the trade-off between privacy and data utility, providing a robust defense against reidentification while preserving data accuracy for practical applications. The findings suggest that the integration of synthetic trace generation with heat map-based obfuscation can significantly enhance the protection of mobility data, offering a stronger solution for privacy-preserving data sharing.