SBAS Authentication Concepts and Trade-offs

Christian Wullems, Luciano Tosato, Daniele Pozza, Andrea Dalla Chiara, Alessandra Calabrese, Mikael Mabilleau, Ettore Canestri

Abstract:	SBAS authentication is a relatively new concept, which is still in the process of being defined and standardised. The aviation community is working to advance in the definition of the SBAS authentication concept. One of the aspects that generates uncertainties in the community is its actual feasibility: authenticating SBAS messages requires a series of complex operations that avionic receivers would have to perform on top of what they already do. The work presented in this paper is a first attempt (to the knowledge of its authors) to assess if the computational processing required to perform SBAS authentication functions could be managed by potential chipsets within avionic receivers. The platforms selected for the benchmarking process, are a result of an engineering judgement on what was deemed to be interesting to the avionic industry, without prior consultation with receiver manufacturers. The authentication scheme considered for the analysis is the one presented by Stanford University [4] (refer also to the related papers [2] and [3]). For this analysis, the authentication functions from an opensource cryptographic library have been implemented in three different platforms: the CPU and memory load that the execution of the authentication functions and algorithms has then been computed, to obtain some figures of merit to be used as reference. Taking into consideration the assumptions and caveats of the benchmarking analysis explained in the paper, results indicate that adding SBAS authentication to avionic receivers is likely to be feasible due to the relatively low impact of cryptographic processing (especially for processing required in real-time). The paper also gives insight on the potential future work to be carried out to confirm the obtained conclusions, and to tackle aspects of SBAS Authentication that need further prototyping.
Published in:	Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022) September 19 - 23, 2022 Hyatt Regency Denver Denver, Colorado
Pages:	69 - 88
Cite this article:	Wullems, Christian, Tosato, Luciano, Pozza, Daniele, Chiara, Andrea Dalla, Calabrese, Alessandra, Mabilleau, Mikael, Canestri, Ettore, "SBAS Authentication Concepts and Trade-offs," Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022), Denver, Colorado, September 2022, pp. 69-88. https://doi.org/10.33012/2022.18308
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