Session A1: Navigation Security and Authentication

Testing Galileo SAS with Encrypted Signal-in-Space
Rafael Terris-Gallego, José A. López-Salcedo, Gonzalo Seco-Granados, Univ. Autonoma de Barcelona/IEEC; Aleix Galan-Figueras, Katholieke Univ. Leuven (KUL); Ignacio Fernandez-Hernandez, DG DEFIS, European Commission
Location: Holiday 1 (Second Floor)
Date/Time: Wednesday, Sep. 10, 9:20 a.m.

Galileo Signal Authentication Service (SAS) provides civil signal authentication by applying spreading code encryption on E6-C and TESLA keys disclosed via OSNMA on E1-B, thus avoiding any long-term secret storage in receivers. After years of development, Galileo has recently conducted encrypted E6-C signal-in-space trials, enabling end-toend SAS testing. This paper reports the first results with encrypted signal-in-space using an SDR-based test-bed that implements the receiver-side SAS workflow: retrieval and parsing of Re-Encrypted Code Sequences (RECS), snapshot recording of E6-C and E1-B, and post-disclosure decryption and correlation. Campaign results confirm successful E6-C detections and validate key configuration parameters in the current specification, including RECS length and period, and the Key Delay Index (KDI). Acquisition is assisted by E1-B, consistent with the nominal SAS operating mode. These results represent a step toward operational SAS, validating the end-to-end transmission and reception chain.