Session A2: GNSS Security: Interference, Jamming, and Spoofing 1

Real-Time Multi-Constellation Navigation Message Authentication for Enhanced GNSS Security
Xifeng Wen, Tor Egil Melgård, Roel De Vries, Erik Vigen, Fugro
Location: Beacon A

The increasing dependence on reliable and secure Positioning, Navigation, and Timing (PNT) services has heightened the need for robust Global Navigation Satellite System (GNSS) protection measures, especially in light of growing vulnerabilities to interference, jamming, and spoofing. These threats have become more prevalent and accessible, posing a tangible risk to critical infrastructure and applications such as transportation, communication, and energy networks. Navigation Message Authentication (NMA) is a fundamental approach for verifying the authenticity of GNSS signals and detecting spoofing attempts. This paper presents the architecture and implementation details of Fugro Atomichron NMA, a multi-constellation NMA solution capable of providing secure, real-time authentication for over 120 satellites.
The paper also presents the results from extensive testing conducted during JammerTest in Norway—the world’s largest open jamming and spoofing test—over a three-year period. The test results demonstrate the effectiveness of Atomichron NMA in detecting and mitigating spoofing attempts under complex, real-world interference scenarios. The system consistently achieved strong performance in terms of detection latency, authentication success rate, and resilience, highlighting its robustness and suitability for enhancing GNSS security in contested environments.
The system architecture of Atomichron NMA is discussed in detail, including a novel scheduling mechanism that ensures real-time NMA transmission in sync with varying navigation message update rates across different constellations. The solution achieves high performance while optimizing bandwidth utilization and computational resources, making it adaptable to a wide range of GNSS applications. The architecture incorporates an automated over-the-air key management system with a multi-level key hierarchy, securely distributing and updating cryptographic keys via satellite. This hierarchy ensures a layered security approach, where different levels of keys are used for various authentication operations, enhancing overall security without manual intervention. Additionally, dynamic signal handling strategies are introduced to mitigate the impact of jamming and spoofing, further improving system robustness.
The findings presented in this paper contribute to the development of advanced GNSS security mechanisms by offering insights into the design and implementation of a multi-constellation NMA system that addresses current and emerging threats. The demonstrated effectiveness of Atomichron NMA under real-world testing validates its capability to provide robust GNSS authentication and integrity assurance, ensuring the continued reliability and security of critical PNT services.