Why Zero Trust?

The traditional network perimeter model is obsolete in the cloud. Attackers may already be inside the network, or identities may be compromised. The Zero Trust model assumes “never trust, always verify” — every request must be authenticated, authorized, and encrypted, regardless of source.

In the exam, Zero Trust principles are often tested through scenario-based questions about securing access, segmenting networks, and enforcing continuous monitoring.

1. Zero Trust Principles

• Verify Explicitly → Authenticate & authorize based on all available data (identity, device, location, risk).

• Least Privilege Access → Give only the access required, and only when required (PIM, RBAC).

• Assume Breach → Design systems assuming attackers may already be inside.

2. Defense-in-Depth

Definition:
A layered security strategy across identities, endpoints, networks, applications, and data.

Layers in Azure:

1. Identity & Access – Entra ID, Conditional Access, MFA, PIM.

2. Perimeter – DDoS Protection, Azure Firewall.

3. Network – NSGs, ASGs, Private Endpoints.

4. Compute – Endpoint protection, Defender for Servers.

5. Applications – WAF, App Gateway, APIM policies.

6. Data – TDE, Always Encrypted, Key Vault, Confidential Computing.

7. Monitoring – Microsoft Sentinel, Defender for Cloud.

3. Designing Zero Trust in Azure

Identity Layer:

• Enforce MFA with Conditional Access.

• Detect suspicious sign-ins with Identity Protection.

• Use PIM for JIT access.

Network Layer:

• Micro-segmentation with NSGs + ASGs.

• Block all by default, whitelist specific traffic.

• Use Private Endpoints for PaaS services.

Application Layer:

• Protect APIs with APIM.

• Enable WAF on App Gateway.

• Use Managed Identities instead of hardcoded secrets.

Data Layer:

• Encrypt data at rest and in transit.

• Store secrets in Key Vault.

• Apply role-based access policies.

Monitoring & Response:

• Use Microsoft Defender for Cloud to enforce baseline compliance.

• Use Sentinel for SIEM + SOAR (detect/respond to threats).

4. Example Enterprise Scenario

A financial institution requires:

• Strong authentication and identity protection for employees.

• Segmented networks with no direct internet access to databases.

• APIs must be protected and rate-limited.

• Threats must be detected and automatically remediated.

Correct design:

• Apply Zero Trust identity policies (CA, MFA, PIM).

• Use NSGs + Private Endpoints for DB tier.

• Protect APIs with APIM + WAF.

• Enable Defender for Cloud + Sentinel for monitoring and automation.

5. Confusion Buster

• Zero Trust vs Traditional Security

  • Zero Trust = verify every request, assume breach.

  • Traditional = perimeter-based, trust internal network.

• Defense-in-Depth vs Zero Trust

  • Defense-in-Depth = multiple layered controls.

  • Zero Trust = mindset + enforcement model.

• PIM vs RBAC

  • RBAC = static role assignment.

  • PIM = JIT, time-limited, least privilege enforcement.

6. Exam Tips

• “Which Azure approach assumes breach and verifies all requests?” → Zero Trust.

• “Which model uses multiple layers like identity, network, data, monitoring?” → Defense-in-Depth.

• “Which Azure service provides JIT access for least privilege?” → PIM.

• “Which feature ensures PaaS resources are never exposed publicly?” → Private Endpoints.

• “Which tool enforces compliance baseline across workloads?” → Defender for Cloud.

7. What to Expect in the Exam

• Direct Q: “What is the principle of Zero Trust?” → Never trust, always verify.

• Scenario Q: “Healthcare company needs network segmentation + private DB access only.” → NSGs + Private Endpoints.

• Scenario Q: “Bank wants least privilege enforcement for Global Admins.” → PIM.

• Scenario Q: “Company requires multi-layered approach including identity, network, data, monitoring.” → Defense-in-Depth.

• Trick Q: “Zero Trust means only external traffic must be authenticated.” → False (all traffic).