Combinatorial Watermarking for GNSS Signal Authentication
Jason Anderson, SHERMAN C. LO, Todd Walter · Proceedings of the Institute of Navigation ... International Technical Meeting/Proceedings of the ... International Technical Meeting of The Institute of Navigation · 2024
Watermarking Signal Authentication can establish trust in satellite navigation signals by cryptographically perturbing the spreading code. In previous work, we propose and derive probability distributions that predict receiver statistics for use in scheme design. In this work, we design a SBAS watermarking signal authentication scheme that can afford 32-bit authentication security over a 6-second time interval, matching the cadence of SBAS navigation message authentication proposals and providing 6-12 second time to authentication. The scheme is immediately extendable to other GNSS services, provided the receiver is observing SBAS signals or is network connected. We design with parameters to match worst-case operating conditions and minimum receiver hardware. We validate our models via Monte Carlo simulation and experiments with real WAAS observation and a software-defined radio to support our scheme proposals.