Zero-Trust architecture on AWS means never trusting any request by default — whether it comes from inside your VPC or from an authenticated IAM user. Every access request must be verified, logged, and scoped to the minimum necessary privilege.
1. Define a Strong IAM Perimeter
Start with SCP-based guardrails at the AWS Organizations level. Deny access to all services not explicitly required. Use permission boundaries to prevent privilege escalation even within allowed roles.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Deny",
"Action": "*",
"Resource": "*",
"Condition": {
"StringNotEquals": {
"aws:RequestedRegion": ["us-east-1", "eu-west-1"]
}
}
}
]
}
2. Network Micro-Segmentation
Divide your VPC into isolated subnets per tier (web, app, data). Use security groups as firewalls with explicit ingress/egress rules. Never use 0.0.0.0/0 — even for “internal” traffic.
3. Continuous Verification with AWS IAM Identity Center
Implement short-lived credentials via IAM Roles Anywhere for non-human workloads. Enforce MFA for all human access and use session tags to pass context-aware policies.
“In a Zero-Trust model, a compromised credential is only useful for seconds — not days. Short-lived tokens and continuous verification make that possible.”
4. Data Encryption Everywhere
Enable S3 default encryption, EBS volume encryption, and RDS encryption at rest. Use KMS with customer-managed keys and automatic key rotation. Encrypt all traffic in transit using TLS 1.3.
5. Monitoring and Auditing
Aggregate CloudTrail, VPC Flow Logs, and GuardDuty findings into a central SIEM. Set up anomaly detection alerts for unusual API patterns — like an EC2 instance assuming an IAM role from an unexpected region.
6. Automate Compliance Checks
Use AWS Config with custom rules to enforce Zero-Trust policies. Automatically remediate non-compliant resources with Lambda functions. Run these checks on a schedule and trigger incident tickets for failures.