Cybersecurity Exposure in Connected Industrial Operations

Plants have added computer vision, condition-monitoring sensors and connected equipment over several years. Each project was approved on its operational merits, and few came with a security review.

The older security model assumed a perimeter, in which inside was trusted, outside was not, and there were few crossings. That model no longer matches the network, because devices from many vendors now sit inside, some with remote access for support and some with default passwords nobody changed.

Operational technology (OT) is the hardware and software that monitors and controls physical processes. Securing it is a specialty of its own, with priorities in a different order from office IT.

Exhibit 1: How IT security and OT security differ in practice.

An IT team applying its normal practice to a control system can cause an outage by itself, and an operations team with no security training can leave a door open for years. The two need to work to a shared plan.

Segmentation means dividing the network into zones and controlling what passes between them. The operational network is separated from the corporate network, and both are separated from anything facing the internet. Within operations, safety systems and control systems are isolated further.

The approach is set out in the Purdue Enterprise Reference Architecture and in the ISA/IEC 62443 series, which describes zones and the conduits between them.

Operators are sometimes sold detection tools before the basics are done, even though those tools assume a segmented network underneath.

• →Do we have one list of every connected device, and who owns it?
• →Which vendors have remote access, and how is it controlled?
• →If the corporate network were compromised tomorrow, could the plant keep running safely?
• →Which control systems can no longer be patched, and how are they protected?
• →Who decides whether a new device may be connected?

The last question matters most for the future. A simple gate at procurement, asking how a device will be segmented and maintained, prevents the inventory from growing unchecked.

Connected devices also raise questions about whether their data can be relied on, which we take up in the data quality problem in industrial IoT.

• →Ask for a current inventory of every device connected to the operational network.
• →Find out whether a device on the plant floor can reach the corporate network, and the reverse.
• →Confirm who is responsible for OT security and whether that person sits in operations or IT.
• →Require a security review before any new connected equipment is installed.