Towards High-Assurance Cross-Domain Solutions for Connected Aviation

Next generation Air Transportation Systems are going to be strongly information-centered and will drive greater integration and connectivity of all the relevant communication endpoints. Focusing on the airborne domain, future communication infrastructures will require more integration among the different aircraft networks, overcoming the traditional partitioning into multiple, isolated security domains. Novel solutions are needed to support a more flexible approach, allowing bidirectional flows across domains with a strong assurance that safety-critical functions are adequately protected from misuse or cyber threats. The paper reports on research conducted to pilot the use of the seL4 microkernel to implement a high-assurance Cross-domain Guard Solution to support communication over domains of different assurance levels and enforce control on packets and payloads allowed to transition across those domains. Such a solution is designed to allow easy reconfiguration of the cross-domain policy while providing the highest guarantees of security by leveraging both the platform hardware security support and the formally-proven-correct seL4 separation kernel. The proposed solution also comprises a toolchain for quick and cost-effective customization and deployment: from the high-level representation of the desired configuration to the auto-generated configuration and integration code for the underlying platform.