Ensuring Cyber Resiliency for OT Systems

Cyber resilience is the ability for an entity to continuously deliver the intended outcome despite cyber-attacks. In this case, the “entity” could likely be your plant and the “intended outcome” is the results produced by your operational technology (OT) efforts. Stated simply, being cyber resilient means your operations stay in operation even though they may be under cyber-attack.

“Cyberworthiness” is an assessment of the resilience of a system from cyber-attacks. It is applicable to software and hardware elements like standalone software, code deployed on an Internet site, browsers, manufacturing equipment or Industrial Internet of Things (IIoT) devices.

Whether intentional—as in a cyber-attack—or unintentional—as in a failed software update—adverse cyber events negatively impact the availability, integrity, or confidentiality of networked OT and information technology (IT) systems and associated services.
 

Cybersecurity versus cyber resilience

Cyber resilience is designed to prevent systems and networks from being derailed in the event that security is compromised. The manufacturing line, refinery or pipeline “stays” operational. Cyber resilience means that cybersecurity is effective without compromising the usability of OT systems (Figure 1).

Need for cyber resilience is real

Hale points out that one of the classic cases of a lack of cyber resilience is the Colonial Pipeline incident a few years back (Figure 2). “There was a ransomware attack on the company’s IT department and while OT systems remained up and capable of running, the company shut down completely for about four or five days ‘out of an abundance of caution.’ The real reason was the company’s billing system was run on the IT side and if that was held for ransom, the company could not bill its customers and therefore not make any money, so they had to shut everything down. Even though OT was not affected, they had no plan on what they should do to stay running in case of an attack.”