A theoretical foundation for location secrecy

Sharing users' positional information is often required for high accuracy localization, which is a cornerstone for numerous wireless applications in commercial, military, and social sectors. This raises a concern of leaking positional information to adversaries during the localization process. This paper establishes a mathematical foundation for location secrecy. In particular, we determine the location secrecy metric (LSM) for a localization network in which an eavesdropper has a generic measurement capability. We obtain a simple and closed-form expression of the LSM for the case where the eavesdropper's measurement of a user's position is corrupted by a Gaussian noise. We further extend this result to a more general measurement model, and design location secrecy protection strategies based on the insights gained from our analysis. The performance of the proposed algorithms is verified through numerical simulation.