Zero Trust Implementation Architecture

Overview

This page provides a detailed technical architecture for implementing Zero Trust in sovereign cloud environments. It covers the components, data flows, decision points, and how all six pillars work together end-to-end.

View Diagram: Zero Trust Architecture for Sovereign Cloud

Zero Trust Architecture showing identity verification, network security, and data protection layers Figure 1: Complete Zero Trust implementation architecture with all security pillars and continuous monitoring

Complete Zero Trust Architecture 

graph TB
    User[User/Device Entry] --> Identity[Identity Verification<br/>Entra ID / AD]
    Identity --> Device[Device Compliance Check]
    Device --> Network[Network Security]
    Network --> App[Application Access]
    App --> Data[Data Access]

    Identity -.-> IAM[• MFA<br/>• Conditional Access<br/>• Risk Assessment]
    Device -.-> Compliance[• OS Version<br/>• Encryption<br/>• Antimalware<br/>• Firewall]
    Network -.-> NetSec[• Microsegmentation<br/>• VPN/SD-WAN<br/>• Private Endpoints<br/>• Monitoring]
    App -.-> AppSec[• RBAC/ABAC<br/>• API Auth<br/>• Rate Limiting<br/>• WAF]
    Data -.-> DataSec[• Classification<br/>• Encryption<br/>• DLP<br/>• Audit Logging]

    Data --> Infrastructure[Infrastructure Security]
    Infrastructure -.-> InfraSec[• VM Hardening<br/>• NSG<br/>• Container Security<br/>• PAM]

    subgraph Monitor[Continuous Monitoring]
        SIEM[SIEM/SOAR]
        Threat[Threat Detection]
        Audit[Audit Logging]
    end

    Identity -.-> Monitor
    Device -.-> Monitor
    Network -.-> Monitor
    App -.-> Monitor
    Data -.-> Monitor
    Infrastructure -.-> Monitor

    style User fill:#D4E9D7,stroke:#107C10,stroke-width:3px,color:#000
    style Identity fill:#E8F4FD,stroke:#0078D4,stroke-width:2px,color:#000
    style Device fill:#E8F4FD,stroke:#0078D4,stroke-width:2px,color:#000
    style Network fill:#FFF4E6,stroke:#FF8C00,stroke-width:2px,color:#000
    style App fill:#FFF4E6,stroke:#FF8C00,stroke-width:2px,color:#000
    style Data fill:#F3E8FF,stroke:#7B3FF2,stroke-width:2px,color:#000
    style Infrastructure fill:#F3E8FF,stroke:#7B3FF2,stroke-width:2px,color:#000
    style Monitor fill:#FFE6E6,stroke:#D13438,stroke-width:2px,color:#000

End-to-End Architecture Components

1. User/Device Entry Point

Initial Request:

  • User initiates access request (application, resource, data)
  • Device sends request with authentication credentials
  • Connection establishes with identity provider

Information Collected:

  • User identity (username, certificate, etc.)
  • Device identifier and state
  • Request context (time, location, network)
  • Application being accessed
  • Requested resource or action

2. Identity & Access Control Layer

Identity Provider (Entra ID, on-premises AD):

  • Verifies user identity
  • Checks credential validity
  • Assesses user risk (impossible travel, anomalous behavior)
  • Applies MFA if required

Conditional Access Rules:

  • Location-based policies (geo-fencing)
  • Device compliance requirements
  • Risk-based policies (user/sign-in risk)
  • Session-based policies (refresh requirements)
  • Application-specific policies

Decision Point 1: Identity Verified?

  • ✓ Yes → Proceed to Device Check
  • ✗ No → Deny access, log attempt

3. Device Compliance Check

Device Health Assessment:

  • Operating system version and patches
  • Antimalware/antivirus status
  • Disk encryption enabled (BitLocker)
  • Firewall enabled and active
  • MFA capability
  • Device enrollment status

Compliance Policies:

  • Corporate-owned devices vs. personal
  • OS type (Windows, macOS, iOS, Android)
  • Required security tools
  • Encryption requirements

Decision Point 2: Device Compliant?

  • ✓ Yes → Proceed to Network Assessment
  • ✗ No → Remediation required or deny access

4. Network & Connectivity Control

Microsegmentation:

  • Network divided into security zones
  • Each zone has explicit policies
  • Traffic between zones strictly controlled
  • Least privilege network access

Secure Access Methods:

  • VPN or SD-WAN requirement (zero-knowledge proof)
  • Private endpoint connectivity
  • Application proxy (no direct internet access)
  • Encrypted tunnels for all traffic

Network Monitoring:

  • Real-time traffic analysis
  • Anomaly detection
  • DDoS protection
  • Intrusion detection/prevention

Decision Point 3: Network Connection Valid?

  • ✓ Yes → Proceed to Application Access
  • ✗ No → Block, alert, investigate

5. Application & API Security

Application-Level Controls:

  • API authentication (API keys, OAuth tokens)
  • Rate limiting per user/application
  • Input validation and sanitization
  • DDoS protection
  • Web application firewall (WAF)

Authorization:

  • Role-based access control (RBAC)
  • Attribute-based access control (ABAC)
  • Fine-grained permissions
  • Time-based access windows

Decision Point 4: Application Access Authorized?

  • ✓ Yes → Proceed to Data Access
  • ✗ No → Deny, log, alert

6. Data Access & Protection

Data Classification:

  • Public, Internal, Confidential, Restricted
  • Tags applied at storage level
  • Inheritance rules for derived data
  • Classification drives protection level

Access Controls:

  • Encryption key tied to identity
  • Audit logging of all access
  • Data loss prevention (DLP) scanning
  • Tokenization for sensitive data

Monitoring & Logging:

  • Who accessed what data
  • When and from where
  • What action (read, modify, delete)
  • Audit trail retention (6-7 years for compliance)

7. Infrastructure & Container Security

Infrastructure Controls:

  • Virtual machine hardening
  • Network security groups (NSG)
  • Managed identity for services
  • Privilege access management (PAM)

Container Security:

  • Container image scanning
  • Runtime security monitoring
  • Pod security policies
  • Network policies in Kubernetes

Decision Point 5: Infrastructure Access Valid?

  • ✓ Yes → Grant access, establish session
  • ✗ No → Deny, alert, investigate

8. Continuous Monitoring & Response

Monitoring Systems:

  • Session monitoring
  • Activity baseline establishment
  • Anomaly detection (ML-based)
  • Compliance audit logging

Real-Time Analysis:

  • User behavior analytics (UBA)
  • Entity behavior analytics (EBA)
  • Impossible travel detection
  • Suspicious activity alerts

Automated Response:

  • Risk-based access adjustments
  • Session termination on high risk
  • Additional MFA challenges
  • Escalation to security team

Feedback Loop:

  • Monitoring data feeds back to conditional access
  • Risk assessments updated in real-time
  • Policies adjusted based on patterns
  • False positive reduction

Decision Flow Summary 

1. User initiates request
   ↓
2. Identity verification
   ├─ ✗ → DENY
   └─ ✓ → Continue
   ↓
3. Device compliance check
   ├─ ✗ → REMEDIATE or DENY
   └─ ✓ → Continue
   ↓
4. Network access validation
   ├─ ✗ → DENY
   └─ ✓ → Continue
   ↓
5. Application authorization
   ├─ ✗ → DENY
   └─ ✓ → Continue
   ↓
6. Data access control
   ├─ ✗ → DENY
   └─ ✓ → Continue
   ↓
7. Infrastructure access
   ├─ ✗ → DENY
   └─ ✓ → GRANT (limited session)
   ↓
8. Continuous monitoring
   ├─ Anomaly detected → CHALLENGE or REVOKE
   └─ Normal activity → Allow, Log

Defense-in-Depth Layering

Layered Defense Example:

Layer 1 - Perimeter: Network firewalls, DDoS protection, intrusion detection

Layer 2 - Access: MFA, Conditional Access, device compliance

Layer 3 - Application: API security, rate limiting, WAF

Layer 4 - Data: Encryption, classification, audit logging

Layer 5 - Infrastructure: VM hardening, network policies, PAM

Layer 6 - Core: Protected resources, encryption keys, sensitive data

If any layer is breached, others still provide protection.

Compliance Mapping

Implementation Patterns

Pattern 1: Centralized Identity (Standard)

Topology:

  • Central identity provider (Entra ID, on-premises AD)
  • All access decisions routed through central system
  • Works for connected environments
  • Single point of management

Pros:

  • Centralized policy management
  • Consistent access decisions
  • Easier compliance auditing

Cons:

  • Dependent on central system availability
  • Not suitable for air-gapped environments
  • Network latency for remote sites

Pattern 2: Distributed Identity (Sovereign/Edge)

Topology:

  • Local identity caches at each site
  • Local policy enforcement
  • Periodic sync with central
  • Works in disconnected mode

Pros:

  • Works without cloud connectivity
  • Faster local decisions
  • Suitable for air-gapped environments
  • Data residency compliance

Cons:

  • Policy sync complexity
  • Potential for policy drift
  • More operational overhead

Topology:

  • Central policy management
  • Local enforcement engines
  • Event log synchronization
  • Periodic reconciliation

Pros:

  • Best of both: central control + local enforcement
  • Works connected or disconnected
  • Suitable for sovereign requirements
  • Flexibility and resilience

Cons:

  • More complex implementation
  • Requires local caching/replication
  • More operational procedures

Sovereign Cloud Considerations

Data Residency

  • All policy decisions made within sovereign boundary
  • No policy data leaves jurisdiction
  • Audit logs stored locally
  • Encryption keys held locally

Customer Control

  • Customer defines all policies
  • Customer reviews access logs
  • No Microsoft infrastructure in policy path
  • Explicit approval workflows possible

Compliance Requirements

  • FedRAMP: Continuous monitoring, explicit controls, audit logging
  • GDPR: Data subject rights, DPA review, encryption
  • HIPAA: Role-based access, audit controls, de-identification
  • ITAR: U.S. person verification, controlled data access

Air-Gap Capability

  • Local identity verification
  • Local policy enforcement
  • Offline access (limited scenarios)
  • Manual sync procedures

Next Steps

  1. Continue to Monitoring & Compliance →
  2. Ready for hands-on work? Lab: Implement Zero Trust →

Last Updated: October 2025