Technology
Zero Trust architecture for public agencies
The principles behind Zero Trust, the maturity model, and a realistic sequence for a small security team.
Zero Trust is a security model in which no user, device, or network location is trusted by default. Every access request is verified against identity, device health, and context, and access is limited to what is needed. It replaces the perimeter model in which anything inside the network was trusted.
Why it fits agencies now
Staff work remotely, applications live in the cloud, field devices roam, and vendors need access. The network perimeter no longer contains the agency's systems, so a model that does not depend on the perimeter is required.
Core principles
- Verify explicitly: authenticate and authorize based on all available signals
- Least privilege: grant the minimum access needed, for the shortest time
- Assume breach: segment, monitor, and limit what any single compromise can reach
Pillars
Zero Trust maturity models, such as the one published by the federal Cybersecurity and Infrastructure Security Agency, organize the work into pillars: identity, devices, networks, applications and workloads, and data, with visibility, automation, and governance across all of them. Each pillar has maturity stages.
A realistic sequence for a small team
- Identity. Multi-factor authentication everywhere, conditional access, and prompt deprovisioning.
- Devices. Management and health checks as a condition of access.
- Application access. Per-application access replacing broad VPN.
- Network segmentation. Separate public safety, utility control, business, and guest traffic.
- Data. Classification, encryption, and access policies based on sensitivity.
- Visibility. Centralized logging and analytics across all of the above.
What to avoid
Buying a "Zero Trust platform" before the basics are in place, or treating Zero Trust as a single project. It is a direction of travel measured by maturity, not a product.
Measuring progress
Assess against a maturity model annually and report to leadership. Early phases deliver visible risk reduction, which sustains support for the later ones.