Security Considerations for IEEE 802.1 Time-Sensitive Networking in Converged Industrial Networks

Cyber security becomes more and more relevant for the domain of Industrial Control System (ICS). An aspect, which increases the attack surface of those devices is the trend of Industry 4.0 and the associated network interconnections. While those devices were air-gapped and communication was clearly segregated, new technologies arise, which break up with this concept, since horizontal and vertical interconnection is essential for future use cases in ICS. Time Sensitive Networking (TSN) represents such a new technology, which allows the transmission of hard real-time traffic, commonly present within the field level communication, converged with other communication streams, e.g. non-time critical best-effort traffic, on the same wire. On the one hand this approach brings many benefits for ICS environments, e.g. predictive maintenance to reduce unplanned downtime, logging and others. But on the other hand this technology enlarges the attack surface of ICS and must therefore be analyzed from a cyber security perspective. For instance the transmission of real-time traffic can be disturbed easily by various network-based attacks, which makes protective measures necessary. Theretore, within this work, security considerations for the use of TSN within ICS applications are presented, suitable protective measures as well as potential enhancements are depicted. The threats and mitigations presented within this work are intended to draw attention towards cyber security within TSN based converged networks and provide an overview for possible protection strategies.