Zero Trust Guide: ZTNA & Architecture Explained

Estimated Read Time: 8 minutes

What is Zero Trust?

Zero trust is a cybersecurity framework that operates on the principle "never trust, always verify." Unlike traditional security models that trust users and devices within the network perimeter, zero trust assumes that threats can exist anywhere - both inside and outside your organisation.

For UK public sector and healthcare organisations handling sensitive data, zero trust provides the rigorous security approach needed to protect against evolving cyber threats while maintaining compliance with NHS Digital, PSN, and HSCN requirements.

Zero trust isn't just a product - it's a strategic approach to network security that Cloud Gateway helps organisations implement through our unified platform, combining connectivity, security, and real-time visibility.

Zero Trust Architecture

Zero trust architecture is the structural framework that implements zero trust security principles across your entire network infrastructure. It creates multiple security checkpoints and verification layers throughout the system.

Key Components of Zero Trust:

• Identity verification and authentication

• Device compliance and security posture

• Application and data protection controls

• Network micro-segmentation

• Continuous monitoring and analytics

For NHS trusts and public sector organisations, zero trust architecture ensures that every access request is authenticated and authorised, regardless of user location or device type.

Zero Trust Network Access (ZTNA)

Zero Trust Network Access (ZTNA) is a security solution that provides secure, contextual access to applications and services based on defined access control policies. It replaces traditional Remote Access VPN solutions with more granular, secure connectivity.

ZTNA Benefits:

• Application-specific access controls

• Reduced attack surface compared to VPNs

• Better user experience with seamless access

• Comprehensive audit trails for compliance

• Support for remote and hybrid working

Cloud Gateway's ZTNA implementation ensures healthcare and public sector staff can securely access critical applications while maintaining full compliance with sector-specific security requirements.

Zero Trust Network

A zero trust network is designed with security controls embedded at every layer, eliminating the concept of trusted internal networks. Every user, device, and application must be verified before gaining access to network resources.

Network Characteristics:

• Micro-segmentation of network resources

• Least-privilege access principles

• Encrypted communications throughout

• Real-time threat detection and response

• Software-defined security perimeters

This approach is particularly valuable for organisations with hybrid IT estates, multiple sites, or cloud-based services—common challenges in UK healthcare and government environments.

Zero Trust Security Model

The zero trust security model is a cybersecurity approach that requires strict identity verification for every person and device trying to access resources, regardless of whether they are inside or outside the organisation's network perimeter.

Core Principles:

• Verify explicitly using multiple data sources

• Apply least privilege access consistently

• Assume breach and verify end-to-end

• Monitor and log all network activity

• Automate security responses where possible

For compliance-heavy sectors like healthcare, this model provides the audit trail and security controls needed to meet regulatory requirements while supporting digital transformation initiatives.

Conditional Access

Conditional access is a zero trust component that uses signals like user location, device compliance, and application sensitivity to make real-time access decisions. It's the engine that applies zero trust policies dynamically.

Decision Factors:

• User identity and group membership

• Device health and compliance status

• Location and network context

• Time of day

• Application sensitivity level

• Risk assessment scores

This enables organisations to balance security with user experience, allowing trusted access while blocking suspicious activity automatically.

Micro-Segmentation

Micro-segmentation divides networks into small, isolated segments to limit lateral movement of threats. Each segment can have its own security policies and access controls, reducing the blast radius of potential security incidents.

Implementation Benefits:

• Contains security breaches quickly

• Enables granular policy enforcement

• Improves network performance monitoring

• Supports regulatory compliance requirements

• Reduces complexity of security management

For NHS trusts managing multiple departments and patient data systems, micro-segmentation ensures that a security incident in one area doesn't compromise the entire network.