Airborne networks need segmentation

Modern aircraft should not run every digital function on one flat network; safety systems need their own lanes, with tightly controlled crossings. (faa.gov) The Federal Aviation Administration said in a September 21, 2023 presentation that new aircraft designs now connect to “non-trusted services” and aircraft data networks, creating cybersecurity risks that older rules did not fully address. The agency said new connectivity can require a fresh security risk assessment when it reaches systems that were previously isolated. (faa.gov) That is the core of Bishop W.C. Martin’s recent advice: split navigation, communications, maintenance, and passenger-service functions into separate zones, then watch traffic between them and lock down each zone. Martin’s post argues that segmentation, monitoring, and hardening should be treated as basic design choices, not add-ons after deployment. (bishopwcmartin.com) In plain terms, segmentation works like fire doors in a building: a problem in one compartment is less likely to spread into the cockpit, radios, or maintenance links. Monitoring means logging and inspecting the traffic that is allowed to cross those boundaries, and hardening means disabling unnecessary services, tightening configurations, and reducing the number of paths an attacker can use. (csrc.nist.gov) Aviation regulators are already moving in that direction. The Federal Aviation Administration published a proposed rule on August 21, 2024 that would add design standards for cybersecurity in transport-category airplanes, engines, and propellers, and said the goal is to standardize how aircraft makers address these threats. (transportation.gov) Europe’s regulator has taken the same position that cyber risk is now a safety issue, not just an information-technology problem. The European Union Aviation Safety Agency says civil aviation is an attractive target for cyberattacks and that cyber risks must be controlled during aircraft design, development, and operation to avoid effects on safety. (easa.europa.eu) The same logic carries beyond aviation because modern networks no longer have one clear perimeter. The National Institute of Standards and Technology said in Special Publication 800-215 that distributed systems, cloud services, and branch networks have expanded attack surfaces and let attackers move across network boundaries by exploiting extensive connectivity. (csrc.nist.gov) That is why Martin extends the idea to campuses and retail chains: isolate payment systems from guest Wi-Fi, building controls from office devices, and store operations from corporate systems. A breach can still happen inside one zone, but segmentation makes it harder for one compromised device to become a network-wide incident. (bishopwcmartin.com)