Nautilus: An Embedded Navigation Authentication Testbed
Cillian O’Driscoll, Gianluca Caparra · Proceedings of the Satellite Division's International Technical Meeting (Online)/Proceedings of the Satellite Division's International Technical Meeting (CD-ROM) · 2021
The vulnerability of GNSS signals to malicious spoofing attacks is a topic that has been gathering increased attention in recent years, and a number of different approaches have been proposed to overcome this vulnerability. Some of these approaches are user side, such as Automatic Gain Control (AGC) monitoring, or the use of an Inertial Measurement Unit (IMU), while others require modifications to the system, such as Navigation Message Authentication (NMA) and Spreading Code Encryption (SCE). In this work we introduce Nautilus, a low-cost, lightweight and highly configurable platform for assessing GNSS authentication schemes. Nautilus consists of a commercially available board integrating a u-blox GNSS receiver, a Raspberry Pi Single Board Computer (SBC) and an LMS7002M Software Defined Radio (SDR). A range of custom software has been developed to enable both system side (NMA and SCE) authentication, and user-side defenses, such as clock modelling, secure time transfer and IMU consistency checks. In this paper, we describe the Nautilus hardware and software architecture, demonstrate some calibration results and finally show some results from live sky testing.