Zero Trust Architecture: Beyond the Buzzword

Zero trust is a security approach that avoids granting implicit trust solely because a user or device is on a particular network. Access decisions use identity, device, resource, and other context. It is an ongoing architecture and operating model, not one product or a guarantee that a breach cannot spread.

In brief: Start by identifying important resources, strengthening authentication, limiting access, and monitoring activity. Improve controls in stages. NIST SP 800-207 and the CISA Zero Trust Maturity Model describe the approach.

What are the core ideas?

Verify access. Authenticate users and devices and evaluate the context of a request. Access policies can be reassessed as conditions change, depending on the systems and tools in use.

Use least privilege. Give people and applications only the permissions needed for their work, review those permissions, and remove them when no longer required.

Limit movement. Segment sensitive systems and control connections between them. Segmentation can reduce an attacker's options, but its effectiveness depends on design and operation.

Monitor and respond. Collect relevant signals, investigate suspicious activity, and use incident response procedures to contain and recover from incidents.

Where should a smaller business start?

1. Inventory critical applications, data, identities, devices, and access paths.
2. Enable multifactor authentication, favoring phishing-resistant methods where supported, and secure administrator accounts.
3. Review permissions and remove unused accounts and excessive access.
4. Manage device updates and health; apply conditional access where supported.
5. Segment high-value systems and restrict remote access.
6. Monitor important systems, test backups, and practice incident response.

Implement these steps in an order that reflects business risk, technical constraints, and available resources. Tools such as Microsoft Entra ID or other identity platforms can support policies, but licensing and capabilities vary.

Do we need to replace the entire network?

No. Zero trust can be introduced incrementally. Begin with high-value resources and close significant access gaps, then extend policies as the environment matures. A mature program also needs ownership and ongoing reviews.

Does zero trust replace a firewall or VPN?

Not automatically. A zero trust design can include network controls and remote-access tools, but avoids treating a network location or a VPN connection as sufficient proof of trust. Evaluate each system's access and risk.

AdVran's cybersecurity and network infrastructure services can help assess and implement controls suited to the environment.

Related reading

• Phishing defense strategy
• SOC 2 readiness
• SOC monitoring for small businesses