Zero Trust Architecture

What is Zero Trust?

Zero Trust is a security framework based on "Never trust, always verify." Unlike traditional perimeter security that trusts everything inside the network, Zero Trust assumes threats exist everywhere.

The concept was introduced by Forrester Research in 2010, but gained mainstream adoption after attacks like SolarWinds and Colonial Pipeline.

Why Traditional Security Failed

• Cloud Adoption: Data lives in AWS, Azure, GCP—outside the perimeter
• Remote Work: Employees access from home, coffee shops, airports
• Supply Chain Attacks: Trusted vendors get compromised
• Lateral Movement: Attackers move freely once inside

"The perimeter is dead. The new perimeter is identity." — Gartner

The 5 Core Pillars

Implementation Guide

Phase 1: Assessment (Months 1-3)

1. Inventory all users, devices, applications, data
2. Map data flows across organization
3. Identify crown jewels (most critical assets)
4. Assess current controls against Zero Trust pillars

Phase 2: Foundation (Months 4-9)

1. Deploy centralized IAM with MFA everywhere
2. Enable SSO to reduce password sprawl
3. Deploy MDM/UEM for device compliance
4. Implement network monitoring and logging

Phase 3: Segmentation (Months 10-18)

1. Write granular access policies (least privilege)
2. Micro-segment networks at workload level
3. Add WAF, API gateways for apps
4. Classify data, implement encryption and DLP

Key Technologies

Category	Tools	Purpose
Identity	Okta, Azure AD, Ping	SSO, MFA
Endpoint	CrowdStrike, Defender	EDR, Compliance
Network	Zscaler, Palo Alto	ZTNA, SWG
Micro-Seg	Illumio, VMware NSX	Workload Isolation
SIEM	Splunk, Sentinel	Detection

Code Examples

Kubernetes Network Policy

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-payment-api
spec:
  podSelector:
    matchLabels:
      app: payment-service
  ingress:
    - from:
        - podSelector:
            matchLabels:
              app: frontend
      ports:
        - port: 443
  egress:
    - to:
        - podSelector:
            matchLabels:
              app: database
      ports:
        - port: 5432

Device Compliance Check (Python)

import platform, subprocess

def check_compliance():
    os_name = platform.system()
    checks = {"os_supported": False, "firewall": False}
    
    if os_name == "Windows":
        checks["os_supported"] = int(platform.release()) >= 10
        fw = subprocess.run(["netsh", "advfirewall", "show", "allprofiles"], 
                           capture_output=True, text=True)
        checks["firewall"] = "ON" in fw.stdout
    
    return checks

print(check_compliance())

Challenges & Solutions

Legacy apps don't support modern auth	Use reverse proxies to add auth layer
User friction with constant MFA	Risk-based auth; step-up only for risky actions
Complex policy management	Policy-as-code (OPA, Cedar)
Shadow IT	CASB for discovery; ZTNA for control

Conclusion

Zero Trust is a fundamental shift in security philosophy. Start today:

1. Enable MFA for all users
2. Inventory critical assets
3. Implement least-privilege access
4. Monitor and log everything

Updated: December 2024