Zero Trust Security For Today’s OT: Core Principles That You Need To Know

Zero trust security is a cybersecurity strategy that goes by the belief that no entity should be trusted by default. It follows the principle of least-privileged access and does not automatically allow any connection before gauging its security posture. Whether it is a device, an app, a service, or a user, trust is established after monitoring the entity’s security protocols and is continually monitored for any anomalies. Even if the entity was authenticated before, it would be subject to re-authentication for every new connection as zero trust means trust is never assumed. This is especially true for Operational Technology (OT).

‍Zero Trust Architecture 

Imagine you live in a neighbourhood where you don't automatically trust anyone who comes to your door, even if they claim to be a friend. In the world of digital security, zero trust is a bit like applying the same cautious mindset to your online interactions.

Traditionally, security systems operated on the assumption that everything inside a network is safe, and anything outside is a potential threat. Zero trust flips this idea on its head. It operates on the principle of “never trust, always verify.” In other words, just because someone or something is inside the network doesn't mean it's automatically trustworthy.

Imagine you're logging into your online banking account. Instead of just entering your password and gaining access, a zero trust system would require additional verification steps. It might ask for a code sent to your phone or email to make sure it's really you trying to access the account, even if you've entered the correct password.

So, in the world of critical infrastructure, zero trust means every user, device, and application is treated as untrusted, and they have to continuously be authenticated. It's like double-checking the identity of everyone in your digital "neighbourhood" to ensure a more secure environment.

‍Core Principles of Zero Trust for OT Environments

A zero trust approach for OT sites helps build a cybersecurity ecosystem that has secure access, device and network segmentation, authentication, and end-to-end visibility across IP and non-IP networks. At the core of zero trust architecture, there are three main principles: 

1. Check Every Connection: Firewalls follow a “passthrough” approach, which means it inspects messages or data packets as they are delivered. What this means is that if a malicious packet is detected, it might be too late to secure the network. A zero trust approach terminates every connection within the proxy architecture and inspects all traffic real time, including encrypted traffic, before it even reaches its destination. This includes applying network segmentation around critical industrial control systems which helps stop any potential threats in the network.

2. Device Protection Based on Behaviour: A zero trust approach verifies access requests and rights based on context. It observes device identity, location, type of usage, and the application being requested. Following this approach helps detect unauthorised devices or “cloned” devices, device tampering, outdated software and man-in-the-middle attacks.

3. Eliminate Attack Surfaces: Zero trust monitoring helps devices directly connect to other devices, apps, and resources operating on heterogeneous networks that are both non-IP and IP-based. This kind of micro-intrusion detection at level 0/1 prevents risking the entry of vulnerabilities through lateral movements from non-critical to critical systems. 

With such an effective zero trust model, you can begin empowering and securing your workforce. MicroSec provides an automated cybersecurity monitoring solution to help you stay on top of your OT cybersecurity game.

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Source: 

https://www.zscaler.com/resources/security-terms-glossary/what-is-zero-trust

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