Zero Trust Network Access: Why Are Top Companies Adopting This Security Model?

Zero Trust Network Access emerged from one undeniable reality, perimeter-based security models were never built to handle today’s threats moving at modern speed.

A single compromised employee account is enough to give attackers unrestricted access across the entire internal network.

Legacy approaches like VPN and firewalls did not fail entirely, they simply became obsolete because they were built on assumptions that no longer reflect how modern businesses operate.

Cloud adoption, workforce mobility, and increasingly sophisticated attacks have fundamentally changed the threat landscape.

What is Zero Trust Network Access (ZTNA)?

Zero Trust Network Access is a network security model based on a simple yet fundamental principle; no user, device, or system should be trusted automatically, even if they are already inside the internal network.

Every access request must be verified based on identity, device posture, location, and situational context before access is granted.

Why Traditional Network Security is No Longer Enough

For years, perimeter-based security models like firewalls and VPNs have been the primary reliance for companies in protecting their digital assets.

However, with the widespread adoption of cloud computing, employee mobility, and the increasing volume of sophisticated cyberattacks, this model has begun to show intolerable gaps.

Here are some fundamental limitations of traditional security models:

• Excessive trust granted to all users once they are inside the internal network.
• Highly limited visibility into user activities after the initial authentication process is complete.
• Difficulty in managing access consistently and securely for a remote workforce and external vendors.
• Inability to keep pace with the rapidly evolving dynamics of cloud environments.

Security Gaps Frequently Exploited in Conventional Networks

The perimeter-based model grants full trust to anyone who has successfully entered the network, and this is the vulnerability most often exploited by attackers.

Once a single access point is breached, attackers can move freely throughout the system without significant obstacles.

These are the most commonly targeted vulnerabilities:

• Lateral Movement: Attackers move freely between systems after gaining initial access.
• Over-privileged Access: Users have access rights that far exceed the actual requirements of their tasks.
• Stolen Credentials: Stolen passwords provide full access as if they were a legitimate user.
• Unmonitored Third-Party Access: Access from vendors or external partners that is not consistently monitored.

Core Principles of Zero Trust Network Access

ZTNA does not merely introduce a new layer of technology on top of legacy infrastructure, it fundamentally changes how organizations view the concept of trust and access.

There are five core principles that form the solid foundation of this model:

1. Never Trust, Always Verify: Every access request must be thoroughly verified, regardless of the user’s location or network status.
2. Least-Privilege Access: Every user receives only the minimum access strictly necessary to complete their tasks.
3. Microsegmentation: The network is divided into small, isolated segments to prevent lateral movement if one segment is compromised.
4. Continuous Monitoring: User activity is monitored continuously, not just during the initial login.
5. Contextual Access Control: Access decisions consider the full context simultaneously, including identity, device, location, and time of access.

How Zero Trust Network Access Works

Zero Trust Network Access automatically verifies every access request before a connection is ever established, granting no implicit trust to anyone by default.

User identity, device health, location, and access policies are all evaluated simultaneously before a narrow path to a specific application is opened.

If any single check fails, for instance the device is missing its latest security update, access is immediately denied without exception. There is no broad tunnel into the entire network the way a traditional VPN operates.

Real-world use case: A manufacturing company with 15 external vendors accessing their ERP system can restrict each vendor to specific modules only, from registered devices, within defined working hours.

That level of granular control is simply not achievable with conventional VPN architecture.

Technical Components in the ZTNA Ecosystem

The ZTNA ecosystem consists of several technical components that work in a coordinated manner to ensure every access decision is made based on accurate data and strict policies.

Business Benefits of Zero Trust Network Access

Adopting ZTNA is not just about tightening security, but also about building a digital ecosystem that is more efficient, controlled, and ready to meet ever-evolving regulatory demands.

The benefits are felt directly from both technical and operational perspectives:

• A significantly reduced attack surface thanks to strict identity- and context-based access.
• Full, real-time visibility into who is accessing what, when, and from which device.
• A more secure remote work experience without sacrificing speed and employee productivity.
• Easier compliance with regulatory requirements such as ISO 27001 and Indonesia’s Personal Data Protection (PDP) Law No. 27 of 2022.
• High scalability because ZTNA runs on flexible, easily expandable cloud infrastructure.

Comparing ZTNA and Traditional VPN

Zero Trust Network Access builds a direct connection to the requested application based on verified identity and context, never to the entire network.

This means that even if credentials are stolen, attackers still have no meaningful room to move laterally. VPN works in the opposite direction: one successful authentication opens access to entire network segments.

That fundamental difference in philosophy is precisely what makes ZTNA far more relevant for today’s digital security demands.

Initial Steps to Implement ZTNA in Your Organization

Transitioning to a ZTNA model does not need to be done all at once and should not disrupt ongoing operations.

A structured and phased approach is key to ensuring a smooth implementation with measurable results from the start.

1. Audit existing identities and access: Map out all users, devices, applications, and data that need protection to build a solid initial foundation.
2. Define role-based access policies: Determine who is allowed to access what based on job functions and their respective risk levels.
3. Implement Multi-Factor Authentication (MFA): Ensure every access requires more than just a password as an additional layer of verification.
4. Apply microsegmentation in phases: Start with the most critical and sensitive segments, then expand across the entire infrastructure systematically.
5. Monitor and evaluate continuously: Use activity logs and security analytics to continuously refine existing policies as threats evolve.

Common Challenges and How to Overcome Them

Zero Trust Network Access offers a significantly stronger security posture, but the path to full adoption is rarely without friction.

Here are the three most common challenges organizations face, along with concrete ways to address each one.

Legacy Systems That Are Not Compatible

Older systems built on conventional protocols are often incompatible with identity-based architectures like ZTNA.

Forcing a direct integration without proper preparation risks disrupting ongoing operations and introducing new vulnerabilities at connection points.

Solution: Use a ZTNA connector with legacy protocol support such as RDP and SSH, then adopt a hybrid approach where old and new infrastructure run side by side throughout the transition phase.

Internal Resistance from Users

Additional authentication steps that never existed before are frequently perceived by employees as productivity obstacles.

Without sufficient understanding, users tend to look for shortcuts that end up undermining the very security being put in place.

Solution: Run internal education sessions before implementation begins and involve representatives from each department during the planning phase. Show them concretely how the new process protects them rather than slows them down.

Policy Management Complexity

The more users, devices, and applications that need to be managed, the more complex the access policy matrix becomes to maintain consistently.

Misconfigurations in overlapping policies can quietly open gaps that go undetected until an actual incident occurs.

Solution: Choose a ZTNA platform with centralized policy management, policy conflict visualization, and automated periodic audits. This allows the IT team to manage hundreds of access rules without having to review each one manually.

Conclusion

Zero Trust Network Access is the right and measured response to the reality that today’s cyber threats can no longer be countered with security models designed before the era of cloud computing and remote work.

Organizations that adopt it early will have a distinct advantage in terms of data protection, operational efficiency, and regulatory compliance readiness.

If your organization is considering its first steps toward a Zero Trust architecture, Adaptist Prime is here as an Identity and Access Management (IAM) solution designed to support that journey comprehensively.

With Identity Governance and Administration (IGA) features, user lifecycle management, and context-based access control, Adaptist Prime helps IT teams efficiently implement the principles of least-privilege access and continuous verification across your company’s digital ecosystem.

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