Keys from the Sky: A First Exploration of Physical-Layer Security Using Satellite Links

TL;DR

This paper explores the use of satellite link properties for physical-layer security to enable secure proximity-based group key establishment and location verification, demonstrating initial feasibility with off-the-shelf hardware.

Contribution

It introduces satellite-based physical-layer security as a novel approach for secure proximity and location verification, with initial experimental validation.

Findings

Feasibility demonstrated with off-the-shelf hardware

Physical-layer security offers post-quantum resistance

Potential for resource-constrained device implementation

Abstract

In this paper, we investigate physical-layer security (PLS) methods for proximity-based group-key establishment and proof of location. Fields of application include secure car-to-car communication, privacy-preserving and secure distance evidence for healthcare or location-based feature activation. Existing technologies do not solve the problem satisfactorily, due to communication restrictions, e.g., ultra-wide band (UWB) based time of flight measurements, or trusted hardware, e.g., using global navigation satellite system (GNSS) positioning data. We introduce PLS as a solution candidate. It is information theoretically secure, which also means post-quantum resistant, and has the potential to run on resource constrained devices with low latency. Furthermore, we use wireless channel properties of satellite-to-Earth links, demonstrate the first feasibility study using off-the-shelf hardware testbeds and present first evaluation results and future directions for research.