The SAP Link: A Controller Architecture for Secure Industrial Control Systems

• Main Author: Wyman, Matthew Cody
• Format: Others
• Published: BYU ScholarsArchive 2019
• Subjects: SCADA; ICS; security; controller architecture; industrial control system; cyber war; safety logic; Electrical and Computer Engineering
• Online Access: https://scholarsarchive.byu.edu/etd/8815; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9824&context=etd

Industrial Control Systems are essential to modern life. They are utilized in hundreds of processes including power distribution, water treatment, manufacturing, traffic management, and amusement park ride control. These systems are an essential part of modern life and if compromised, could result in significant economic loss, safety impacts, damage to the environment, and even loss of life. Unfortunately, many of these systems are not properly secured from a cyber attack. It is likely that a well-funded and motivated attack from a nation-state will successfully compromise an industrial control system's network. As cyber war becomes more prevalent, it is becoming more critical to find new and innovative ways to reduce the physical impacts from a cyber attack.This thesis presents a new architecture for a secure industrial controller. This architecture protects the integrity of the controller logic, including the safety logic which is responsible for keeping the process in a safe condition. In particular, it would prevent malicious or accidental modification or bypassing of the controller logic. This architecture divides the controller into three components; the logic controller, the interface controller and the SAP link. The logic controller is responsible for controlling the equipment and contains the safety logic. The interface controller communicates with the rest of the control system network. The Simple As Possible (SAP) link is a bridge between the logic and interface controllers that ensures the integrity of the logic controller by drastically limiting the external interface of the logic controller. We implement this new architecture on a physical controller to demonstrate the process of implementing the architecture and to demonstrate its feasibility.