Analyzing sensitive information leakage in trajectory embedding models

Abstract

With the proliferation of the mobile networks and location-based services, huge volume of user trajectories are collected to analyze the similarity among users and further unveil human mobility patterns for downstream tasks, such as point-of-interest recommendation and tourism planning. In recent works, trajectory embedding methods have been studied as efficient ways of trajectory similarity computation and effective inputs for downstream tasks, which embed trajectories into latent vector spaces equipped with the Euclidean distance to approximate the trajectory similarity and capture the characteristics of human mobility patterns. However, we demonstrate that such embedding, though hiding the locations, can leak the sensitive information of the trajectories, combined with auxiliary data. In this work, we propose trajectory embedding attack schemes to analyze the sensitive information leakage of the embedding vectors. In the experiment, we demonstrate that the passing areas, visited ROIs, and exact shapes of the trajectories are vulnerable under attacks on embedding vectors by the adversary with auxiliary information.