Impact analysis of SBAS authentication

The GNSS community is dedicating significant effort to protect applications from harmful interference, including spoofing. As part of this effort, Europe will authenticate the Galileo Open Service message and is currently evaluating authentication schemes for EGNOS. This article presents the main results of recent EU activities on EGNOS authentication. After presenting some examples that illustrate the importance of authenticating SBAS, this article describes the main drivers for SBAS authentication design, namely, the use of I and/or Q channels, the use of the L1 and/or L5 frequencies, the authentication latency, and the cryptographic parameters. Later, the article presents the performances of EC-Schnorr and TESLA data authentication schemes and analyzes their impact in the SBAS L1 message sequence and in the L1/L5 Dual Frequency Multi-Constellation Standard message sequence, currently under development.