Challenges and prospects of communication security in real-time ethernet automation systems

Abstract

Real-Time Ethernet has become the major communication technology for modern automation and industrial control systems. On the one hand, this trend increases the need for an automation-friendly security solution, as such networks can no longer be considered sufficiently isolated. On the other hand, it shows that, despite diverging requirements, the domain of Operational Technology (OT) can derive advantage from highvolume technology of the Information Technology (IT) domain. Based on these two sides of the same coin, we study the challenges and prospects of approaches to communication security in realtime Ethernet automation systems. In order to capitalize the expertise aggregated in decades of research and development, we put a special focus on the reuse of well-established security technology from the IT domain. We argue that enhancing such technology to become automation-friendly is likely to result in more robust and secure designs than greenfield designs. Because of its widespread deployment and the (to this date) nonexistence of a consistent securiy architecture, we use PROFINET as a showcase of our considerations. Security requirements for this technology are defined and different well-known solutions are examined according their suitability for PROFINET. Based on these findings, we elaborate the necessary adaptions for the deployment on PROFINET.

Secure Links: Secure-by-Design Communications in IEC 61499 Industrial Control Applications

“…Bidirectional communications using the client/server model may use TLS between application slices deployed onto multiple devices. However, secure multicast communication is challenging in ICS when using Datagram TLS or IPSECbased virtual private networks [9]. Other challenges of applying TLS may include performance tradeoffs, channel multiplexing, constrained components, time synchronization.…”

“…Selective protection of "data of interest" helps in better system performance while ensuring adequate security. In such cases, a blanket approach like TLS may induce latency overheads [9].…”

“…Third, traditional methods may require more resources than are available on resource-constrained PLCs. Subsequently, maintaining a balance between the demands of communication security in ICS becomes a key challenge [9]. Hence, for an ICS application developer, the only available option to protect against such attacks is to include communication security mechanisms manually into the application.…”

PROFINET Real-Time Protection Layer: Performance Analysis of Cryptographic and Protocol Processing Overhead

“…This is not only very time consuming but also may not be of highest priority since in most use cases the transmitted data may not be confidential. b) Implementation Principles: Almost all existing security solutions are designed and implemented for the use in standard office IT environment and therefore quite certainly not suitable for the usage in operation technology (OT) networks without adaption [10]. Nevertheless, solutions to protect PROFINET communication should build upon wellestablished and widespread standards.…”

Protecting PROFINET cyclic real-time traffic: A performance evaluation and verification platform

“…A body of work on optimizing PROFINET IRT for fast cycle times [6] states typical system boundaries of such applications: 8 to 256 Bytes payload and 250 µs cycle time with a 50:50 real-time to non-real-time traffic duty cycle. The challenges on finding suitable solutions for protecting PROFINET and general real-time Ethernet automation systems as well as corresponding requirements were investigated in [7], In Section II we elaborate the performance overhead produced by additional protocol fields for protecting PROFINET real-time traffic as well as a brief theoretical background on proposed cryptographic building blocks. Section III describes the ongoing work of the prototypal implementation of a security switch.…”