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Zero Trust
Definition
Zero Trust is a security model based on the principle "never trust, always verify". No user, device or system automatically receives access, regardless of whether it is inside or outside the network.
Zero Trust is a security model based on the principle of never trust, always verify. In a Zero Trust architecture, no user, device or network connection is automatically trusted, regardless of whether it is inside or outside the corporate network. Forrester Research estimates that organisations implementing Zero Trust reduce their risk of data breaches by 50%.
How does Zero Trust work?
In the traditional security model, everything inside the corporate network is considered trusted (castle-and-moat). Zero Trust abandons this concept entirely. Every access request is individually verified based on identity, device status, location, behaviour and the requested resource. Continuous verification means access is not granted once but constantly reassessed. The principle of least privilege ensures users and systems have only the minimum required rights. Microsegmentation divides the network into small, controlled zones.
The five pillars of Zero Trust
Identity: strong authentication via MFA and risk-based access policies. Devices: continuous verification of device status, compliance and security posture. Network: microsegmentation and encrypted traffic. Applications and workloads: secure access to applications regardless of location. Data: classification, encryption and access control at data level.
Impact on organisations
The shift to hybrid working, cloud adoption and IoT has dissolved the traditional network perimeter. Employees work everywhere, data resides in multiple cloud environments and IoT devices connect to the network. The castle-and-moat model no longer provides adequate protection in this reality. NIS2 requires organisations to implement appropriate technical measures reflecting the current threat environment. ISO 27001 emphasises risk-based access control. DORA sets ICT risk management requirements aligned with Zero Trust principles. The NIST Zero Trust Architecture framework (SP 800-207) provides a reference model for implementation.
Protection
Zero Trust implementation is a journey, not a project. Start with identity-centric security: strong MFA, SSO and conditional access policies. Implement endpoint verification via EDR. Apply network segmentation and migrate to microsegmentation. Classify data and apply encryption. Continuously monitor all access and behaviour via SIEM and XDR. Automate response via SOAR.
How DEFION helps
DEFION supports organisations in designing and implementing a Zero Trust strategy through Security Advisory Services and CISO-as-a-Service. Pentests and red teaming validate the effectiveness of the Zero Trust implementation. The MXDR service provides continuous monitoring aligned with Zero Trust principles.