Workforces are no longer confined to office walls. Employees work from cafes, airports, shared spaces, and home networks. But most corporate network security still relies on outdated assumptions: that what’s inside the network is safe and what’s outside isn’t.
Virtual private networks (VPNs) were designed to create a secure tunnel into that “safe” perimeter. The problem is, there’s no clear perimeter anymore.
Once a user connects through a VPN, they often gain broad access to the network. If that user’s credentials are compromised, attackers can move freely, access sensitive data, and stay hidden for weeks. This model of implicit trust breaks down completely in a modern cloud-first, remote-access environment.
That’s why businesses are replacing perimeter-based security with a zero trust approach. It changes the starting assumption: no user or device is trusted by default.
Start on a clear path to secure hybrid working: Hybrid Workplace Security and Device Management
Why VPNs are a Weak Link in Your Network Architecture
VPNs were built for a simpler time, when users worked inside the office and applications sat in a central data center. They were never designed for modern environments that include:
- Distributed teams across multiple time zones
- Cloud services with constantly shifting endpoints
- Unmanaged personal devices
- Third-party vendors accessing specific applications
Here’s what goes wrong when businesses rely solely on VPNs:
1. Overexposure of Corporate Network Resources
Once authenticated, a VPN gives access to the broader network. There’s no granular control over what specific applications a user should access.
- One compromised login can expose critical systems.
- Lateral movement by bad actors often goes undetected until damage is done.
This model increases the risk of data breach significantly, especially with remote workers using mixed-use or unmanaged devices.
2. No Device Posture Checks
VPNs rarely evaluate the security status of the device connecting. Whether it’s up to date, protected by endpoint security, or already compromised is often unknown.
- That gap makes VPNs ineffective in blocking risky or non-compliant devices.
- IoT devices connected to home networks can serve as indirect attack paths.
3. Inflexibility in Cloud Environments
Cloud services are now the backbone of modern IT. VPNs route traffic back through a central network, which creates latency and performance issues.
- This slows down access to tools like Microsoft 365, CRMs, and other cloud platforms.
- It also increases dependency on on-prem infrastructure that no longer reflects actual usage.
4. No Support for Continuous Monitoring
VPNs authenticate once, then step back. There’s no ongoing verification of identity, behavior, or device risk after initial access.
This breaks the core security principle of “never trust, always verify” that underpins a true zero trust model.
Map out your security strategy to make sure zero trust architecture fits in: How to Develop a Cyber Security Roadmap and Build Resilience
What is a Zero Trust Network?
So, the main question: how does zero trust network access work?
Basically, zero trust networking is a strict change in how access is granted, managed, and revoked across your network architecture.
Instead of trusting everything inside your corporate network, zero trust assumes no user or device is inherently safe, regardless of location or credentials. Every connection must prove itself continuously, not just at login.
At the core of zero trust are three key concepts:
1. Identity is the New Perimeter
Each person, system, or device must prove who they are using strong identity and access management (IAM). This includes:
- Multi factor authentication (MFA)
- Single sign on (SSO)
- Conditional access based on location, device health, or behavior
If identity can’t be verified, access is blocked. Automatically.
2. Access is Narrow and Purposeful
Users should only access what they need. Nothing more.
- Access is limited to specific applications, not entire networks
- Permissions are based on least-privilege roles
- Sessions can expire automatically to reduce exposure
This structure dramatically reduces the risk of attackers moving laterally through your systems.
3. Assume Breach and Monitor 24/7
Even trusted users can become threats. Continuous monitoring watches for signs of compromise or abnormal behavior.
- Anomalies trigger immediate security responses
- Policies adapt in real time based on context
- Every request is checked, not just the first one
Together, these controls form a trust approach that fits how businesses operate today: across time zones, platforms, and cloud security needs.
Core Principles of a Zero Trust Network Model
To make zero trust real, organisations need more than just good intentions. They need systems that enforce verification and limit exposure at every level.
The following are core components that turn theory into a working security model:
1. Strong Identity and Access Management
When it comes to zero trust, IAM is foundational. It verifies users and devices before granting access to anything.
- MFA adds another layer of verification beyond passwords
- SSO simplifies authentication without sacrificing control
- User permissions align with roles and responsibilities
Together, they create a gate that can’t be easily bypassed.
2. Device Compliance and Endpoint Security
Zero trust policies check the health and compliance status of the device making the request.
- Unpatched, jailbroken, or unmanaged devices can be denied access
- IoT devices are monitored and segmented to contain risk
- Remote wipe and quarantine tools reduce the blast radius of compromise
You control who and what gets access, not just where they’re logging in from.
3. Microsegmentation
Break your network into smaller zones. Don’t treat everything as one big open space.
- Users can only interact with systems and data relevant to them
- Sensitive data is isolated from general access
- Applications are treated as discrete, protected assets
This limits exposure and makes movement inside the network much harder for attackers.
4. ZTNA Solutions
Zero Trust Network Access (ZTNA) replaces traditional VPNs with smarter, application-level access control.
- Access is brokered per session, per application
- Traffic is encrypted and contextual
- No access is granted unless verified: never trust, always verify
ZTNA is the operational engine behind many modern zero trust deployments.
5. Ongoing Monitoring and Response
Security doesn’t stop after login. You need ongoing visibility.
- Track logins, application use, and file access in real time
- Automate alerts for unusual behavior or failed access attempts
- Feed data into SIEM or XDR systems for broader analysis
With continuous monitoring, security teams can keep security threats at bay.
Are your security measures aligned with the nation’s leading cyber security framework? Double check them here: ASD Essential 8 Compliance: A Security Checklist
How Zero Trust Network Architecture Differs to Traditional Security
Zero trust networking isn’t just a better version of what came before. It’s a fundamental redesign of how access and trust are handled inside your organisation.
Most legacy systems still operate under the assumption that users inside the firewall are safe. That assumption doesn’t hold in remote or hybrid environments.
Here’s how the two models compare:
Traditional Security
- Broad network access
- One-time authentication
- Implicit trust on internal users
- Flat network structure
- VPN as primary access method
- No device checks
Zero Trust Network Security
- Access to specific applications only
- Continuous monitoring of activity and context
- Never trust, always verify
- Microsegmented environment
- ZTNA solutions enforce per-session access
- Access based on user or device compliance
With traditional models, once a user connects, they often gain access to large sections of the corporate network. Regardless of whether they need it.
In contrast, a zero trust approach limits exposure from the start and adapts in real time.
Implementing Zero Trust Network Security Architecture
Zero trust isn’t something you ‘switch on.’ It’s implemented in phases, with each layer reducing risk and building toward a more secure foundation.
Here’s how to start:
1. Map Your Users and Devices
Know who is accessing your systems and from where.
- Create an inventory of all users, endpoints, IoT devices, and service accounts
- Understand which cloud services and internal apps they use
- Identify gaps in visibility and control
You can’t secure what you don’t see.
2. Strengthen IAM
Adopt tools that enforce identity-first security.
- Enforce multi factor authentication (MFA) for all users
- Set up single sign on (SSO) to simplify control
- Apply conditional access policies based on role, location, or device status
3. Prioritise Access to Sensitive Data
Not all systems carry equal risk. Start where it matters most.
- Restrict access to sensitive data based on job function
- Apply security measures like encryption and logging
- Segment applications from the broader network
4. Deploy the Right ZTNA Solutions
Replace or supplement your VPN with zero trust access tools.
- Grant access to specific apps, not full network segments
- Verify every session based on context
- Ensure logging is in place for all access attempts
Make sure your distributed workforce is using the right tools: Hybrid Work Best Practices: Tech and Tips
It’s Time to Rethink Trust
By verifying each user or device, limiting access to specific applications, and enforcing continuous monitoring, a zero trust security model reduces risk without slowing your teams down.
It protects your data and systems, without assuming anything – or anyone – can be trusted by default.
At Planet6, we specialise in curating secure, sustainable IT environments for hybrid and remote work environments.
Reach out to our team about the practical steps needed to secure your distributed workforce.