Cloud Assurance4-minute readAugust 2025

Zero Trust and Cloud Security Assurance

Boards approve cloud migrations. They rarely approve the access model that governs who can reach critical workloads once the migration is complete. Zero Trust is the architectural principle that makes that governance question explicit.

An organisation that has moved critical workloads to cloud without an explicit access governance model has replaced a perimeter it understood with an environment it cannot easily audit.

The migration decision and the assurance gap

Cloud migration removes the network perimeter that traditional security controls were designed to protect. The migration decision is typically framed around capability, cost and delivery. The question of how access to critical workloads will be governed after migration is often addressed at a technical level without board visibility, treated as an implementation detail rather than a governance decision.

Zero Trust provides the governance framework for access to cloud workloads: who can reach what, under what conditions, and how that access is reviewed. That framework is a governance decision, not a technical one, and it belongs in the same approval process as the migration itself.

What the board should be asking

Zero Trust gives a board three specific questions to put to its security leadership. Who owns the policy governing access to cloud workloads, and what does that policy say? Which workloads are critical, and who currently has access to them? And how is that access reviewed, at what frequency, and by whom?

These questions are not answered by default in most cloud programmes. Traditional security governance was built around the network perimeter: if a user was inside, access was assumed. Cloud removes that boundary. Zero Trust replaces the perimeter assumption with access governance that is explicit, documented and reviewable. For a board, the assurance question changes from whether the perimeter is secure to whether access to critical workloads is governed and reviewed on a defined cycle.

A practical test for the board

If the three questions in the previous section can be answered from current reporting without special preparation, the access governance model is working at board level. If they require preparation that falls outside normal reporting cycles, the model is either absent or not surfacing to board oversight.

An organisation may have documented access policy internally without it reaching board accountability or regular review. Access managed at an operational level, with no board oversight and no escalation mechanism, carries the same governance gap as having no policy. The question to put to security leadership is not whether a policy exists, but whether it governs access at a level the board can account for.

How this affects your organisation

If your organisation has completed or is planning a cloud migration, the question of access governance is already live. Zero Trust provides the framework; the board's role is to ensure someone owns it, reports against it and reviews it on a defined cycle.

A board that cannot answer those three questions from its current reporting does not have effective oversight of cloud access, whatever the security team has documented internally.

Does your cloud migration have an access governance model the board can account for?