Summary
In conclusion, we can say that ZTA is a long-term plan for many organizations following Industry 4.0. However, it should be started early with a vision to achieve the principles of ZTA in the long term. Doing so also ensures that network segmentation is achievable through the Purdue model or variations of it. Security at every network segment is critical as we have seen that a breach at any point can lead to lateral movement and compromise of the physical IT/OT/IoT assets, as explained in the kill chain. The security can further be enhanced by using data diodes and their one-way transfer functionality.
In the next chapter, we will learn more about attacks and threat vectors in the OT/IoT environment.