Trajectory recovery

Definition: Trajectory recovery is a type of privacy attack where an adversary reconstructs a person’s movement path (trajectory) over time using partial, anonymized, or aggregated location data. Even when direct identifiers are removed, patterns in the data can reveal where someone has been.

Context/Example: A dataset of “anonymous” GPS pings from a city’s transportation app is released for research. An attacker cross-references the time and location patterns with public information (like home or workplace locations) and reconstructs an individual’s daily travel route—identifying where they live, work, and their habits.

Related Concepts: Location Privacy, Re-identification Attacks, Mobility Data, K-anonymity, Differential Privacy, Spatiotemporal Data, Deanonymization