Converging Safety and Security: IO-Link Wireless and OPC UA over 5G under prEN 50742
Cryptography and Security
Summary
The authors studied how adding cybersecurity measures to wireless safety systems in factories affects performance. They tested a full control chain using different network types: Ethernet, Wi-Fi 6, and private 5G. They found that the extra security made data frames bigger, which limited how many devices could connect wirelessly. Also, private 5G maintained reliable timing needed for safety better than Wi-Fi 6, even though it had slightly higher average delays. This research helps understand trade-offs in combining safety and security in industrial networks.
Authors
Henry Beuster, Thomas Robert Doebbert, Gerd Scholl
Abstract
The integration of wireless communication technologies in industrial automation offers greater flexibility, but also exposes safety systems to a broader threat vector. Emerging regulations, such as the draft standard prEN 50742, mandate the convergence of functional safety and cybersecurity by requiring cryptographic security mechanisms directly in safety-critical communication. This paper presents an empirical evaluation of this safety-security convergence across a complete control chain, spanning from an IO-Link Wireless Safety device to a PLC via an OPC UA backbone. We measure the latencies and jitter of different Safety-Related Security Levels under prEN 50742 over Ethernet, Wi-Fi 6, and private 5G. Our results reveal that while cryptographic execution time is negligible, the resulting frame payload expansion severely restricts wireless fieldbus capacity, reducing the maximum number of devices per IO-Link Wireless track from 8 to 2. Furthermore, we demonstrate that, despite higher average latency, a private 5G provides sufficiently deterministic latency characteristics to preserve functional safety watchdog margins, unlike unlicensed Wi-Fi 6.