  With the rise of data-driven methods for traffic forecasting, accident
prediction, and profiling driving behavior, personal GPS trajectory data has
become an essential asset for businesses and emerging data markets. However, as
personal data, GPS trajectories require protection. Especially by data
breaches, verification of GPS data ownership is a challenging problem.
Watermarking facilitates data ownership verification by encoding provenance
information into the data. GPS trajectory watermarking is particularly
challenging due to the spatio-temporal data properties and easiness of data
modification; as a result, existing methods embed only minimal provenance
information and lack robustness. In this paper, we propose W-Trace - a novel
GPS trajectory watermarking method based on Fourier transformation. We
demonstrate the effectiveness and robustness of W-Trace on two real-world GPS
trajectory datasets.
