PKI-Based Security for Industrial Automation Systems Using 5G Campus Networks

The rapid emergence of Industry 4.0 factory automation necessitates ultra-low latency, high reliability, seamless connectivity, and robust security, driving the adoption of 5G private campus networks. However, these networks encounter considerable challenges in smart factories, where the convergence of operational technology (OT) and information technology (IT) significantly heightens cyber-attack risks. To mitigate these threats, ensuring mutual authentication between all communicating parties is critical. In Industrial IoT (IIoT) settings, SIM card-based authentication poses challenges, including limited scalability, reliance on mobile network operators, and the complexity of managing large fleets of SIM-enabled devices. Conversely, public key infrastructure (PKI)-based authentication provides greater flexibility and convenience for handling cryptographic credentials, private keys, certificates, and trust anchors within 5G environments. This paper discusses the management of cryptographic credentials to enable certificate-based authentication for IT/OT systems in 5G campus networks. Achieving comprehensive security requires a unified architecture that encompasses network, endpoint, and traffic protection. We propose a novel security model for 5G industrial campus networks in brownfield environments, mapping and implementing our abstract security model, which is aligned with the latest standards.