For decades, enterprise security revolved around a simple idea: build a strong perimeter, keep threats outside, and trust everything inside the network. Firewalls, VPNs, and network segmentation formed the backbone of this model. But that assumption is now breaking down.
As enterprises move to cloud-first architectures, adopt remote work, enable BYOD policies, and expose applications over the internet, the traditional “castle-and-moat” approach no longer holds. Attackers no longer need to breach the perimeter directly. Once inside, flat networks and broad access rights allow them to move laterally with ease.
This is where Zero Trust security comes in.
Zero Trust is not a product
One of the most common misconceptions around Zero Trust is that it is a tool or a security product that can simply be purchased and deployed. In reality, Zero Trust is a security strategy and mindset, not an application.
In a recent interaction with TelecomTalk, enterprise security expert Kishore Bitra explained that Zero Trust is a collection of principles designed to reduce risk by assuming that no user, device, or application should ever be trusted by default even if they are already inside the network.
The core assumption of Zero Trust is simple but powerful: assume breach. Enterprises must operate as if attackers are already present and continuously verify every access request.
Why firewalls alone are no longer enough
Traditional security models focus heavily on perimeter defence. Once a user successfully connects via VPN or passes through a firewall, they are often trusted implicitly. This creates multiple risks.
First, lateral movement becomes easy. If one system is compromised, attackers can quickly move across the network. Second, VPNs expand the attack surface by providing broad network-level access. Third, static access controls grant permanent privileges that are rarely reviewed or revoked. Finally, visibility drops sharply once access is granted, making it harder to detect abnormal behaviour.
Zero Trust addresses these weaknesses by shifting security controls closer to the user, device, and application — not just the network edge.
The core idea behind Zero Trust
At its heart, Zero Trust enforces least-privilege access and continuous verification. Access is evaluated per session, per request, and based on multiple signals such as user identity, device health, location, behaviour, and overall risk posture.
Being authenticated once does not grant blanket access. Access to one application does not imply access to another. Policies are dynamic and adapt in real time based on context.
In simple terms, Zero Trust asks three questions every time access is requested:
- Who is the user?
- What device are they using?
- Should they be allowed access at this moment?
Zero Trust is an architecture, not a switch
Another key point highlighted during the TelecomTalk interaction was that Zero Trust should not be treated as a one-time security project. It is a continuous journey, not a destination.
Zero Trust architectures rely on multiple systems working together identity platforms, device management tools, threat intelligence feeds, policy engines, and enforcement points. These systems constantly collect signals, evaluate risk, and enforce access decisions.
As attackers evolve, Zero Trust policies must evolve too. Simply implementing multi-factor authentication or deploying a new security tool does not make an enterprise “Zero Trust ready.”
Why Zero Trust matters now
The shift to cloud services, SaaS applications, remote work, and AI-driven attacks has fundamentally changed the threat landscape. Firewalls still matter, but they are no longer sufficient on their own.
Zero Trust reflects this new reality. It recognises that trust is often the weakest link in modern enterprise environments — and removes it by design.
For enterprises, the message is clear: security can no longer be about strong walls alone. It must be about continuous verification, granular access, and constant improvement.
