The U.S. Department of Homeland Security (DHS) Science and Technology Directorate (S&T) has published a GPS Receiver Whitelist Development Guide and a new release of the Positioning, Navigation, and Timing (PNT) Integrity Library to protect against GPS spoofing.
The free resources are intended to advance the design of PNT systems and increase resilience of critical infrastructure to PNT disruptions.
The GPS Whitelist Development Guide presents a software assurance approach to addressing potential vulnerabilities and increasing reliability of GPS receivers. The guide addresses data-related requirements in the Resilient PNT Conformance Framework, which provides guidance for defining expected behaviors in resilient PNT equipment.
“We hope this guide and related resources will help industry advance towards a cybersecurity-based approach to PNT resilience,” said S&T Technical Manager Ernest Wong.
Originally released in March 2021 as open source on GitHub, the PNT Integrity Library provides users with a method to verify the integrity of the received GPS data. The update includes:
- A compliance check on Interface Control Document (ICD) IS-GPS-200, which is a formal means of establishing, defining and controlling communication between the GPS space and other user systems; and
- A Do-It-Yourself (DIY) Toolkit, which describes how a perspective end-user of the PNT Integrity Library can assemble a demonstrational toolkit with commercial-off-the-shelf (COTS) hardware.
“Since GPS signals can be jammed or spoofed, critical infrastructure systems should not be designed with the assumption that GPS data will always be available or will always be accurate,” said S&T Project Manager Brannan Villee. “Application of these tools will provide increased security against GPS disruptions. However, DHS also recommends a holistic defense strategy that considers the integrity of the PNT data from its reception through its use in the supported system.”