Zero trust is a security model built on the principle of never trusting by default and always verifying. Instead of assuming that anything inside the network is safe, every request is verified using identity, device, context and risk before access is granted, and access is limited to what is needed.

What are the principles of zero trust?

• Verify explicitly: authenticate and authorise every request using all available signals.
• Use least privilege: give only the access needed, and only for as long as needed.
• Assume breach: design as if an attacker is already inside, and limit what they can do.

Why has zero trust become important?

The perimeter that once separated inside from outside has dissolved. Applications are in the cloud, people work from anywhere and attackers often use valid credentials, so a trusted network location no longer means a trusted request.

What are the pillars of zero trust?

Models commonly describe identities, devices, networks, applications and workloads, and data. Each is protected with its own controls, and decisions draw on signals from all of them.

What role does identity play?

A central one. Every decision starts with who or what is asking. That makes strong authentication, conditional access, least privilege, just-in-time access and continuous evaluation core parts of zero trust, for non-human identities as well as for people.

Is zero trust a product?

No. It is a strategy and an architecture, described for example in NIST SP 800-207. Vendors sell components that help, but no single product delivers zero trust on its own.

How does a zero trust decision work?

A person requests access to an application. The system checks who they are, how strongly they authenticated, the state of their device, their location and the sensitivity of the application. It then grants, limits or denies access and keeps evaluating while the session lasts.

What are common mistakes?

• Buying a product and treating zero trust as done.
• Verifying only at login.
• Ignoring service accounts, keys and AI agents.
• Skipping monitoring after access is granted.
• Trying to change everything at once.

Why is monitoring part of zero trust?

Assuming breach means checking continuously, not only at the door. An identity that passed every check can still be compromised, so what it does afterwards has to be watched and compared with what is normal.

How is zero trust different from perimeter security?

Perimeter security trusts what is inside the network and tries to keep attackers out. Zero trust gives no implicit trust to any request, whatever its origin, and limits what any identity can reach, so that a breach does not become free movement.

What are the benefits?

A smaller blast radius when something goes wrong, better visibility of who and what has access, consistent controls across cloud, on-premises and remote work and a clearer basis for justifying access to auditors.

Does zero trust slow people down?

Not if it is done well. Adaptive policies ask for extra verification only when risk is higher, and strong, convenient methods such as passkeys make the safe path the easy one.

How do you start?

Inventory identities and assets. Strengthen identity with MFA and conditional access. Apply least privilege, starting with privileged and non-human identities. Segment critical systems. Monitor behaviour and iterate.

How does zero trust relate to regulation?

NIS2 and DORA do not require zero trust by name, but they expect risk-based access control, strong authentication, monitoring and incident detection, which zero trust supports.

Sharelock supports zero trust on the identity side: it shows where access is excessive, and monitors behaviour after login, down to individual transactions and queries on critical applications.

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