Security fundamentals

What is zero trust?

Zero trust is a security model that assumes no user or device is trusted by default, even inside the network, and verifies every access request based on identity, device health, and context. Its guiding idea is "never trust, always verify."

Definition

Zero trust is an approach to security in which no request is trusted based on network location alone. Every access to a resource is authenticated, authorized, and evaluated against context before it is granted.

Background

The old model trusted anything inside the corporate network perimeter. Remote work, cloud, and modern attacks broke that assumption. Zero trust, described in references such as NIST SP 800-207, replaces implicit trust with continuous verification: verify identity and device explicitly, grant least-privilege access, and assume breach so that a compromise in one place does not open everything. It is an architecture and a mindset rather than a single product.

Why it matters

When trust is implicit, one compromised device or account can move laterally across everything. Zero trust shrinks that blast radius by checking every request, which is increasingly the expectation for modern, cloud-based, remote-friendly organizations.

Step by step

1. Know your assets, identities, and data flows, you can only protect what you can see.
2. Verify every access explicitly using identity and device signals.
3. Enforce least privilege and segment access so lateral movement is hard.
4. Assume breach: monitor continuously and design to contain, not just prevent.
5. Adopt incrementally, starting with the highest-value systems and identities.

Examples

• Access to an internal admin tool requires a verified identity and a healthy, managed device, regardless of network location.
• A compromised laptop cannot reach production because access is segmented and continuously verified.

Common mistakes

• Treating zero trust as a single product to buy rather than an architecture to adopt.
• Verifying at login only, instead of continuously and per-request.
• Trying to do everything at once instead of starting with the crown jewels.

FAQ