The notion of Integrated Modular Avionics (IMA) refers to inter-connected pieces of avionics equipment supported by a wired technology, with stringent reliability and safety requirements. If the inter-connecting wires are physically secured so that a malicious user cannot access them directly, then this enforces (at least partially) the security of the network. However, substituting the wired network with a wireless network - which in this context is referred to as an Avionics Wireless Network (AWN) - brings a number of new challenges related to assurance, reliability, and security. The AWN thus has to ensure that it provides at least the required security and safety levels offered by the equivalent wired network. Providing a wired-equivalent security for a communication channel requires the setting up of a strong, secure (encrypted) channel between the entities that are connected to the AWN. In this paper, we propose three approaches to establish such a secure channel based on (i) pre-shared keys, (ii) trusted key distribution, and (iii) key-sharing protocols. For each of these approaches, we present two representative protocol variants. These protocols are then implemented as part of a demo AWN and they are then compared based on performance measurements. Most importantly, we have evaluated these protocols based on security and operational requirements that we define in this paper for an AWN.
@cite_12: Mobile devices are becoming part of modern digital avionics. Mobile devices can be applied to a range of scenarios, from Electronic Flight Bags to maintenance platforms, in order to manage and configure flight information, configure avionics networks or perform maintenance tasks (including offloading flight logs). It can be argued that recent developments show an increased use of personal mobile devices playing an integral part in the digital avionics industry. In this paper, we look into different proposals for integrating mobile devices with various avionics networks -- either as part of the Bring Your Own Device (BYOD) or Corporate Owned Personally Enabled (COPE) paradigms. Furthermore, we will evaluate the security and trust challenges presented by these devices in their respective domains. This analysis will also include the issues related to communication between the mobile device and the aircraft network via either wired or wireless channels. Finally, the paper puts forward a set of guidelines with regards to the security and trust issues that might be crucial when enabling mobile devices to be part of aircraft networks.
@cite_7: Integrated Modular Avionics (IMA) in existing deployments is a collection of inter-connected avionics equipment supported by wired technology, with stringent reliability and safety requirements. If the inter-connecting wires are physically secured so that a malicious user cannot access them directly, then this simplifies the security management of the network. However, substituting the wired network with a wireless network - also referred to as an Avionics Wireless Network (AWN) - brings a set of new challenges related to assurance, reliability, and security; even for a specific set of well-defined and non-critical tasks. The AWN has to ensure that it provides at a minimum the existing required levels of safety offered by the equivalent wired network. These challenges are underpinned by a necessity to boot the AWN to a secure and trusted state, before it can be used to bridge different parts of the IMA in an aircraft. In this paper, we discuss the security and trust challenges an AWN boot process might face, along with highlighting a potential solution. Finally, the paper evaluates the proposed validation solution that meets the stated security requirements, based on the security challenges discussed.
@cite_17: Avionics networks have a set of stringent reliability and safety requirements. In existing deployments, most of these networks are based on wired technology which provides a high degree of reliability and safety. Furthermore, it simplifies the security management of the network since certain assumptions, including an inability for an attacker to access the network, can be safely made. The proposal for having an Avionics Wireless Network (AWN), currently being developed by multiple aerospace working groups, promises reduction in the complexity of electrical wiring harness design and fabrication, reduction in wiring weight, increased configurability, and potential monitoring of otherwise inaccessible moving or rotating aircraft parts. While providing these benefits, the AWN must ensure that it provides, at a minimum, equivalent levels of safety to those offered by the wired network. Substituting the wired network with a wireless network, even for a specific set of well-defined and non-critical tasks, brings a whole set of new challenges related to assurance, reliability, and security. In this paper, we discuss the security and trust challenges an AWN deployment might face, along with highlighting potential directions for solutions. Furthermore, as a case study we will elaborate on AWN deployment variants especially the wireless as a comm-link. Finally, the paper makes suggestions that set the agenda for security, reliability and trust work that could, if successful, provide an AWN system meeting the required safety standards.
Security and the general deployment of AWNs based on wireless-as-a-comm-link have been analyzed in @cite_17 , which discusses the security and trust challenges faced by AWNs. Beside this, a crucial component of the security of aircraft devices is the trusted boot process discussed in @cite_7 . The security, trust and assurance issues related to bringing a user device into an aircraft network are evaluated in @cite_12 .