Zero Trust is a security principle in which users, devices, and services are not automatically trusted based on their network location. Access to systems and data must be based on verified identities, defined permissions, and relevant security requirements. The principle can be applied across an organization's networks, applications, and broader IT infrastructure.

What does "never trust, always verify" mean in practice?

The principle means that access must be verified and authorized according to applicable security requirements. A user or service should not automatically receive access to additional resources simply because it has already been authenticated or is connected to an internal network. Security controls can also consider device security posture, permissions, and the context of each access request.

Why is Zero Trust becoming more important with artificial intelligence?

Artificial intelligence enables organizations to automate increasingly complex tasks. AI agents can retrieve information, analyze data, and perform actions on behalf of users and organizations. This creates a greater need for clear rules governing which resources agents can access and which actions they are authorized to perform. Zero Trust provides principles for controlling these permissions and reducing the risks associated with extensive automation.

Why is traditional perimeter security no longer sufficient?

Traditional perimeter security largely focuses on protecting an organization's network boundaries. As employees work remotely, services move to the cloud, and applications communicate across different environments, these boundaries become less effective as the basis for access control. Zero Trust places greater emphasis on protecting individual resources and verifying access regardless of network location.

How do remote work and cloud services increase the need for Zero Trust?

Remote work and cloud services allow employees, devices, and applications to operate outside traditional corporate networks. This makes it increasingly difficult to rely on physical location or internal network connectivity as indicators of trust. Zero Trust enables organizations to base access decisions on identity, security posture, and permissions, regardless of where a user or service is located.

What new security challenges do AI agents introduce?

AI agents can operate autonomously, interact with other systems, and execute sequences of actions. If an agent receives excessive permissions, errors, misuse, or compromise can have consequences across multiple systems. Organizations therefore need visibility into agent identities, permissions, and activities. Monitoring agent behavior and restricting the actions agents can perform are also important security measures.

How can Zero Trust principles be applied to AI agents?

Zero Trust principles can help establish clear boundaries around the systems, data, and actions AI agents are allowed to access. Security controls may include dedicated digital identities, explicit authorization, restricted permissions, and validation of actions against organizational security policies. Access should reflect what an agent needs to complete a specific task, while organizations retain the ability to monitor and revoke permissions.

Why is identity and access management important in a Zero Trust architecture?

Identity and access management enables organizations to control who or what is requesting access to their resources. In a Zero Trust architecture, this includes people, devices, applications, and automated services. Effective identity management helps ensure that access is associated with verifiable identities and restricted to the permissions necessary for each task.

Is Zero Trust a single security solution or an overarching principle?

Zero Trust is an overarching security principle implemented through multiple technologies and security controls. Identity management, access control, network security, and monitoring are examples of areas that can contribute to its implementation. Purchasing a single product does not necessarily establish Zero Trust. The security controls must work together as part of a coordinated architecture.

Can Zero Trust replace traditional firewalls?

Zero Trust does not eliminate the need for traditional firewalls. Firewalls can still protect networks, control traffic, and support segmentation. However, access decisions should not depend exclusively on whether traffic originates inside or outside the corporate network. Firewalls can therefore remain one of several security controls within a Zero Trust architecture.

How are SASE and Zero Trust related?

SASE combines networking capabilities and cloud-delivered security services to provide secure access to applications and resources. These solutions can support Zero Trust implementation by enforcing identity-based access controls and security policies. However, Zero Trust is a broader security principle that also applies to other parts of an organization's IT environment.

How can an organization begin implementing Zero Trust?

Organizations should begin by assessing their existing security architecture, critical resources, identities, and access patterns. They can then identify where current security controls rely on implicit trust and determine which areas present the greatest risks. A gradual implementation allows organizations to prioritize improvements across identity management, networking, applications, and access control.

Sicra helps organizations develop security architectures aligned with Zero Trust principles. Through our Zero Trust maturity assessment , we evaluate existing security controls, identities, networks, and applications to identify opportunities for improvement. We also offer identity and access management maturity assessments and network security consulting , helping organizations prioritize concrete measures and develop security architectures tailored to their needs.

Reintroducing Zero Trust in the age of AI

We have already experienced a major shift in working habits and technology adoption that has challenged many of the security principles on which traditional security architecture was built.

The AI wave therefore comes shortly after organizations have navigated the major transition to remote work and cloud services.

In 2025, I gave a presentation at Sikkerhetsfestivalen about this very shift: From chaos to control: How to succeed with SASE transformation.

For many years, security was primarily about protecting the network. Zone-based security models ensured that internal services were delivered from data centers behind advanced firewalls, while users connected from physically secure office locations.

This traditional perimeter-based model worked as long as organizations could maintain control and ownership of their own network perimeters.

AI makes Zero Trust more important than ever

The way we work has changed significantly. Users can work from anywhere, services are delivered from the cloud, and the network perimeters we once relied on have effectively disappeared.

Many organizations have responded to this shift by adopting the Zero Trust principle of "never trust, always verify." Applying Zero Trust principles is becoming increasingly important with the growing adoption of AI.

It is no longer just your users or services that access files, perform actions, or present analyses. AI agents now do these things as well. How can we maintain control?

Zero Trust as a security principle

Throughout my years working in IT security, I have repeatedly seen new technologies and concepts emerge as the latest buzzwords in the industry.

Cloud, Software-Defined WAN (SD-WAN), Software-Defined Access (SDA), machine learning (ML), Development Network (DevNet), Infrastructure as Code (IaC), and now Artificial Intelligence (AI), to name just a few.

Against this backdrop, I have noticed that principles such as Zero Trust are often oversimplified and presented as a single solution or implementation. In my view, this is highly misleading.

From my perspective, Zero Trust is a principle that should guide all security implementations. A Zero Trust network therefore consists of several different implementations working together to verify and validate everything that happens within the network.

Through a series of blog posts, I will explore several security concepts that I believe fall under Zero Trust and are necessary to establish it across different layers and areas of an organization's infrastructure.