For nearly over 20 years, the idea of perimeter-based network and application security model has been used and implemented by organisations worldwide that assume everyone inside the network to be trusted—while everyone outside the network is untrustworthy. 

However, with the evolving technology and the increase of high-profile and sophisticated cybersecurity attacks—the perimeter-based security solution became less relevant and useful for organisations.

This was when a new and more robust security solution came into the picture—Zero Trust Network. Unlike the perimeter-based model—Zero Trust offers software-based and application-based security and works on the principle of “Never Trust, Always Verify”.

In simple terms—no matter inside or outside the network, Zero Trust considers everyone to be untrusted and only provides specific resource access to users after strict authentication and authorisation.

In this article, we’ll learn how the Zero Trust Network Access solution has evolved over the years and how it benefits your organisation’s network security.

Five Phases of Zero Trust Evolution

Zero Trust Network solutions are built for modern enterprises and fulfil their requirements much more efficiently.

Here are the five phases of its evolution over the past few years.

1. Segmentation

The first phase—segmentation, dates back to the 1980s when VLANs came into the picture but gained popularity in the early 2000s. The idea was to break the network into logical segments and limit user access once the user gets into the network.

This phase essentially limited the lateral user movement—minimising many security and data breaches. The latest upgrade of this phase is the micro-segmentation that takes the concept of segmentation to the next level—isolating network segments to specific servers and workloads.

It also helped provide specific user access to the employees, third-party vendors, and contractors to reduce data breaches.

2. SDP Appliances

Early SDPs combined a controller, client software, and a gateway device to offer remote access to on-premise applications without VPNs—reducing the attack surface and shrinking the perimeter to specific applications or resources.

However, right after their emergence—SDPs quickly became expensive and complex to set up, especially for the users that required minimal and infrequent access for non-employees.

3. Identity-based

The next phase of the Zero Trust model was Identity and Access Management (IAM)—which puts forward an identity-based approach.

This approach basically leans towards verifying and authenticating users and their devices using the exiting technologies like SSO/IDaaS, Multi-factor Authentication (MFA), and PAM.

4. Man-in-the-middle Cloud

Content Delivery Networks (CDNs) were the next logical phase in the Zero Trust security model that acts as a platform for users and employees to access remote internal applications without VPNs.

CDNs were essentially used to reduce the effectiveness of the man-in-the-middle attacks—routing all the traffic to the cloud for inspection and verification of the application of policies and then providing application or resource access.

5. Cloud Integration

The last phase of the Zero Trust Network building security was the cloud-integrated approach, where most organisations and enterprises relied on cloud solutions like AWS and Azure instead of CDNs.

This allows organisations to leverage the existing cloud investments to integrate and deliver a Zero Trust framework for network security. Another advantage of this approach is the data security—allowing organisations to integrate security tools like IAM, MDM, PKI, and EDR with the Zero Trust framework across different network endpoints.


With over 76% of organisations using the Zero Trust Security model—it has become the new-age solution for organisations to ensure the utmost network security and protection against security breaches.

Thus, if you wish to implement Zero Trust Security for your organisation’s network security—you can check out InstaSafe solutions that provide affordable and secure solutions to ensure secure remote access for your organisation.

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