Rethinking Security: Zero Trust in Critical Infrastructure

In the UK, critical infrastructure is under siege from digital adversaries who operate in the shadows. That is why Zero Trust is no longer a choice; it is a necessity. Microsoft’s Zero Trust approach operates on the assumption that breaches will happen, so it continuously verifies every access request. 

It has strict access controls and uses tools like Microsoft Entra ID, Conditional Access, and Microsoft Defender for Cloud Apps to make sure that only trusted users and devices can interact with vital systems.

Last year, over 40% of global ransomware attacks targeted critical infrastructure sectors, with the UK energy sector and healthcare among the most frequent victims. 

Traditional firewalls and perimeter defences are crumbling in the face of these sophisticated threats. That is why zero-trust security has become the new baseline. 

Here is how and why big organisations are moving beyond tradition with the zero trust security framework.

Zero Trust in the Real World

Security teams have heard “zero trust” so many times it has started to lose meaning. But for those of us in the trenches, zero zero-trust security framework is a real, practical approach that actually makes a difference.

The main idea behind zero trust security is “don’t trust, always check.” That means every time someone tries to log in or access data, whether it is an engineer in the office or a contractor connecting remotely, you verify who they are, what device they are using, and if they really need access right now. Identity management in zero trust is everything.

Our infrastructure (energy, water, healthcare) runs on more tech than ever. That is great for efficiency, but every new sensor, cloud dashboard, or remote access point is one more way in for attackers.

Most of the big incidents are simple stuff like missed software updates, old systems nobody got around to replacing, or someone clicking a phishing link. UK stats show that about 93% of industrial control system cybersecurity issues are down to these basics.

Step-by-Step Zero Trust Security

Microsoft’s six-pillar model is a solid starting point for any organisation serious about securing critical infrastructure with zero trust.

1. Identity & Access Management

You start by locking down who can get in. Strong passwords alone are not enough anymore. Use extra steps like multi-factor authentication, check if the device is secure, and make sure each login request matches the user’s usual patterns. 

Tools like Microsoft Entra make it easier to enforce identity management in zero trust when teams are spread across sites.

2. Device/Endpoint Security

Every endpoint, whether it is a workstation or a mobile device, has to be visible and secured. Defender for Endpoint and Azure Arc are great for keeping an eye on both cloud and on-prem devices. This step protects OT networks.

3. Network & Micro-segmentation

The days of flat, open networks are over. With network micro-segmentation, you break the environment into smaller zones. If a breach does happen, segmentation helps contain it fast and prevents attackers from moving sideways through your critical systems.

4. Infrastructure Hardening

Assume every part of your infrastructure could be targeted. That is why you apply explicit verification, stick to baseline configurations, and use continuous monitoring. Microsoft Defender for Cloud’s CSPM and CWPP tools help keep your configurations tight and your posture strong.

5. Data Protection

Make sure to control the flow of sensitive data. Classification, encryption, and strict governance are must-haves, specifically in zero trust for healthcare infrastructure or financial operations. The goal is to send data only where it is supposed to go.

6. Threat Detection & SecOps

With threats getting smarter, visibility is everything. You will get a unified view and real-time response capability with tools like Defender for Cloud, Microsoft 365 Defender, and Sentinel. 

Microsoft Defender for Cloud in Infrastructure

When it comes to protecting modern infrastructure, Microsoft Defender for Cloud has become a backbone for many organisations in the UK. It is built on a CNAPP framework that combines Cloud Security Posture Management (CSPM) for your environment’s overall health, Cloud Workload Protection (CWPP) for specific assets, and strong DevSecOps support. This setup gives you real-time insight into both your cloud and on-premises resources.

Hybrid and multi-cloud environments are now the norm, not the exception. Defender for Cloud, together with Azure Arc, means you can manage and secure assets across different platforms. It is ideal for organisations with complex footprints.

Speaking of the “crown jewels,” Defender for Cloud lets you tag and prioritise your most critical resources, so you can focus security alerts and controls where they matter most. This targeted approach is important for securing critical infrastructure with zero trust and ensuring compliance with the UK critical infrastructure security standards.

Regulatory Drivers and Industry Signals

Zero trust compliance requirements are not coming from the IT department only; they are being driven by new regulations and industry mandates. The US Executive Order 14028 and the EU’s NIS2 directive both require robust MFA, strong encryption, and a shift to zero trust for critical infrastructure.

Even the Pentagon is moving towards a Microsoft E5 Zero Trust model by 2027. If your organisation is part of the national backbone, regulators expect you to move beyond traditional security models. The UK is closely aligning with these global signals and making zero-trust security mandatory for staying compliant and resilient.

How Mazik Global Puts Zero Trust to Work

At Mazik Global, we have spent over 20 years helping businesses secure their cloud environments. As a Microsoft Solutions Partner, we are deeply connected with Microsoft’s entire cloud ecosystem, from Azure to Microsoft 365, Dynamics 365, and Power Platform. This expertise makes us a trusted partner for organisations looking to level up their cloud security and make sure their systems are as safe and resilient as possible.

Here is how we actually make zero trust work on the ground.

1. Managed Security + MDR

Mazik Global delivers end-to-end protection for critical environments through managed security services. Acting as a Microsoft-focused MSSP, Mazik provides proactive threat protection, around-the-clock monitoring, and rapid incident response. This lets platforms like Microsoft 365 Defender, Defender for Endpoint, and Sentinel. 

This setup brings a managed detection and response (MDR) capability to your organisation, so you get a dedicated security team that works as an extension of your own IT, which is important for tackling zero trust implementation challenges and modern threats.

2. Azure & Infrastructure Hardening

Mazik’s Azure Management Services ensure that cloud and hybrid workloads are always optimised and secure. We help organisations in the UK energy, health, and utilities sectors meet stringent critical infrastructure security standards with continuous monitoring, automated patching, and hardened baseline configurations. 

3. Comprehensive Microsoft Stack Coverage

Our expertise covers the full Microsoft ecosystem, including Digital Workplace and Dynamics, Data & AI, and App Development etc. This range allows Mazik to integrate identity management in zero trust, governance, and security controls seamlessly across all business applications and infrastructure. 

We include secure data pipelines, automated policy enforcement, and advanced telemetry in our approach to strengthen SecOps and insider threats.

4. Public Sector Use Cases

Mazik Global has a proven track record with mission-critical solutions like MazikCare (healthcare), PowerGov (public sector grants and permits), and ShopFloor (manufacturing operations). 

Each product is designed and deployed with zero-trust security best practices in mind. Mazik enables organisations to run secure, compliant, cloud-native and hybrid environments, with SOC-monitored, least-privilege access, encryption, and integrity across sensitive government and infrastructure workloads.

How to Get Started with Zero Trust

Getting started with zero-trust security for critical infrastructure does not have to be overwhelming. The smartest way forward is to begin with a maturity assessment using frameworks like CISA, NIST SP 800-207, or Microsoft’s own Guidance Centre. This helps you pinpoint where you stand and what matters most for your sector.

Next, pilot practical measures. Try network micro-segmentation and multi-factor authentication in one department. See what works, adjust, and then scale up across your estate.

The final step is to automate wherever possible. With Secure Score, policy-based controls, and tight integration between SecOps tools, you can keep improving without constant manual effort. 

Conclusion

A failure in critical infrastructure is a risk to national security and public trust. That is why zero trust for the energy sector, healthcare, and utilities is no longer up for debate. It is the foundation.

With Defender for Cloud, a robust zero-trust architecture explained, and modern SecOps, your organisation can build true infrastructure resilience. 

At Mazik Global, we go beyond simply setting up Microsoft security tools for you; we make sure they work seamlessly for your business. From running proactive security assessments and providing real-time monitoring to guiding you through compliance and offering hands-on user training, we help protect your organisation from security breaches while preparing you to thrive in the future with a strong, resilient cloud security strategy.