Zero Trust Architecture

Zero trust principles, microsegmentation, identity-based access, and implementation.

Overview

Zero trust assumes no implicit trust, verify everything.

Core Principles

1. Verify Explicitly
   - Always authenticate
   - Use all available data

2. Use Least Privilege Access
   - Just-in-time access
   - Just-enough-access

3. Assume Breach
   - Minimize blast radius
   - Segment access
   - Verify end-to-end

Zero Trust Architecture

+-------------------------------------+
|           Policy Engine              |
|  (Identity, Device, Context)        |
+-------------------------------------+
|           Policy Enforcement         |
|  (Gateway, Proxy, Agent)            |
+-------------------------------------+
|           Resources                  |
|  (Applications, Data, Services)     |
+-------------------------------------+

Microsegmentation

# Network segments
segments:
  - name: dmz
    subnets: [10.0.1.0/24]
    policies:
      - allow: [http, https]
        from: internet
  - name: application
    subnets: [10.0.2.0/24]
    policies:
      - allow: [8080]
        from: dmz
  - name: database
    subnets: [10.0.3.0/24]
    policies:
      - allow: [3306]
        from: application

Identity-Based Access

# Context-aware access
def check_access(user, device, location, resource):
    score = 0
    
    # Identity verification
    if user.mfa_verified:
        score += 30
    
    # Device compliance
    if device.compliant:
        score += 25
    
    # Location risk
    if location in trusted_locations:
        score += 20
    
    # Time of access
    if is_business_hours():
        score += 15
    
    # Resource sensitivity
    if resource.classification == "public":
        score += 10
    
    return score >= 70

Implementation Steps

1. Identify — Assets, data flows
2. Protect — Microsegmentation
3. Detect — Continuous monitoring
4. Respond — Automated response
5. Recover — Resilience

Zero Trust Tools

Practice

Design a zero trust architecture for a hybrid cloud environment.