It was the night before end-of-quarter, and all through the plant, factory floor systems were breaking down because IT flagged a security violation on a safe but rarely used industrial process, and sandboxed a critical subnet.
The poetic legacy of Clement Clarke Moore is secure: My rhymes will never achieve the immortality of "A Visit from St. Nicholas," a.k.a. " 'Twas the Night Before Christmas," but that doesn't make this stark warning about the dangers of the convergence of information technology (IT) with operational technology (OT) any less timely.
IT and OT have two entirely separate histories and objectives.
IT largely exists to solve challenges that were historically addressed by quill-and-ink, abacuses, ledger books, file cabinets and typewriters. Providing employee access to Salesforce.com is IT; so is a deployment of Microsoft Office 365, sending and receiving email, building and running websites, social media and engaging in e-commerce.
By contrast, OT is the factory floor and everything involved in it, from forklifts to assembly lines to packaging to shipping. Centrifuges in a pharmaceutical lab, ovens in a bakery, forges in a steel mill, printing presses for a newspaper and computer-controlled lathes.
These are all operational systems.
There is clearly overlap, and there's more overlap all the time, as industrial processes become more interconnected with computers. Internet of Things (IoT) technologies permeate every aspect of OT these days: forklifts, bakers ovens, centrifuges and presses are monitored by computers and controlled by computers. (See Why CISOs Need a Seat at the IoT Projects Table.)
When computer-controlled manufacturing first came on the scene, it was limited in scope, and almost always restricted to a few devices. Those devices often weren't networked at all, or if they were networked, existed on their own industrial-control LANs. Frequently those were proprietary networks, with specialized protocols at every layer of the network stack.
Those OT networks were usually managed by the factory-floor team: The same folks who maintained the printing press also set up and managed its controlling servers, terminals and networks, often with help from the hardware manufacturers. It was a specialized network, and was beyond the realm of the company's IT staff. In fact, there may have been a strict hands-off policy, with minimal interfaces bridging the operational systems with the corporate LAN.
For many reasons, including security, let's keep those worlds separate. Admittedly, it's going to be more difficult, especially if those manufacturing and other operational systems need to access cloud resources -- or if some well-intentioned people want to connect them to the Internet.
You don't want bad actors accessing your ERP systems, your customer database or financial filings. Those would be damaging. But you certainly don't want those bad actors being able to read OT sensors -- or change industrial controllers. That would be disastrous. Imagine the difference between a hacker or foreign agent being able to subvert a water company's billing systems verses being able to launch a distributed denial of service (DDoS) attack against its hydroelectric dam controls. Or being able to change the temperature on a steel mill's furnace. Or being able to control the ventilation on a petrochemical refinery's distillation tower?
Here are seven rules for keeping OT systems safe and secure, and protecting the product, the plants and the people living nearby:
- Don't connect disparate OT networks to each other. Maintain air-gaps between them
- Don't connect any OT networks to the corporate IT LAN
- Don't let IT staff come within 100 yards of any OT networks
- If OT networks need cloud resources, use dedicated links and keep traffic off the Internet
- Encrypt everything, even on a controlled network
- Require strong authentication everywhere. Trust nothing
- If an executive suggests IT and OT convergence, make sure security is the primary concern, far outweighing cost-savings or convenience
As in the bad poetry above, the IT staff doesn't understand the OT systems, nor is there any reason for them to do so. Keep the good actors out. Keep the bad actors out. You can be sure that St. Nick's OT network controlling the miniature sleigh and eight tiny reindeer can't be hacked by a spearphishing email, or shut down by an over-eager security analyst.
Let's keep it that way.
— Alan Zeichick is principal analyst at Camden Associates, a technology consultancy in Phoenix, Arizona, specializing in enterprise networking, cybersecurity and software development. Follow him @zeichick.