Design Drivers and New Trends for Navigation Message Authentication Schemes for GNSS Systems

GNSS has become a mature technology yielding reliable position, navigation and timing solutions upon which many applications are built. Its widespread adoption has turned into an incentive for malicious actions that, by exploiting GNSS vulnerabilities, aim at either disrupting or precisely modifying the PNT computation. Authenticating the GNSS signal at both the ranging and data levels is a proper way to detect and/ or mitigate such threats. This article discusses the design drivers for GNSS authentication, reviews the predominant navigation message authentication proposals for a GNSS open service, and proposes a novel scheme based on the amortization of digital signatures.