WAWA: Wavelet Analysis-Based Watermarking Authentication for GNSS Civil Signal with Immediate Symbol-Level Verification

TL;DR

WAWA is a new GNSS authentication method that enables immediate verification of signals using wavelet analysis, improving security and efficiency for time-sensitive applications.

Contribution

WAWA introduces a wavelet-based watermarking scheme for GNSS signals that allows immediate symbol-level authentication with low memory and latency.

Findings

WAWA enables immediate symbol-level authentication using a public key, eliminating verification delay and time synchronization.

The method achieves superior effective bandwidth and low memory overhead while maintaining signal integrity.

WAWA's design is validated through theoretical modeling and simulation, showing controllable signal correlation loss.

Abstract

Existing GNSS authentication schemes suffer from critical drawbacks such as high verification latency and prohibitive memory requirements, leaving time-sensitive applications vulnerable to spoofing. The core challenge is the inability to transmit strong, real-time cryptographic credentials through the bandwidth-limited GNSS signal. This paper introduces WAWA, a Wavelet Analysis-based Watermarking Authentication scheme that operates at the physical layer of the GNSS signal. The central innovation of WAWA is its use of the wavelet domain to achieve a high-capacity data channel, allowing a complete public-key digital signature to be embedded directly within the signal structure. This enables receivers to perform immediate, symbol-level authentication using a public key, which fundamentally removes the verification delay and reliance on time synchronization seen in conventional methods. Furthermore, it eliminates the need for large memory buffers, a critical barrier for resource-constrained devices. We present the complete design of the watermark generation, embedding, and extraction process, alongside a novel dual-path verification framework adaptable to both standalone and network-assisted receivers. Performance analysis shows that WAWA achieves immediate authentication while offering superior effective bandwidth and maintaining low memory overhead. Although it introduces a controllable signal correlation loss, validated through both theoretical modeling and simulation, WAWA presents an exceptional balance of security, immediacy, and resource efficiency, offering a promising new paradigm for ensuring trustworthy PNT sensor data in time-critical and resource-sensitive applications, particularly in large-scale sensor networks and autonomous systems.

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