Achieving PCI DSS Compliance on Amazon EKS: A Financial Services Success Story

When a leading financial institution approached STAQI Technologies to modernize their payment processing infrastructure while maintaining strict PCI DSS compliance, we knew we were facing a challenge that would test every aspect of our expertise in secure, high-volume transactional systems.

The Challenge: Modernization Meets Compliance

Our client, a major payment processor handling over 10 million transactions daily, was running their critical payment systems on legacy infrastructure. They needed to:

• Migrate to cloud-native architecture using Amazon EKS
• Maintain PCI DSS Level 1 compliance throughout the transition
• Ensure zero downtime during migration
• Improve performance and scalability
• Reduce operational overhead

The complexity lay not just in the technical migration, but in ensuring that every component of the new EKS infrastructure met the stringent requirements of PCI DSS standards.

Architecture Design: Security-First Approach

Network Isolation and Segmentation

We designed a multi-layered network architecture that provides complete isolation for payment processing workloads:

# Network Policy Example - Cardholder Data Environment
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: payment-processing-isolation
  namespace: pci-scope
spec:
  podSelector:
    matchLabels:
      app: payment-processor
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          name: api-gateway
    ports:
    - protocol: TCP
      port: 8080
  egress:
  - to:
    - namespaceSelector:
        matchLabels:
          name: database
    ports:
    - protocol: TCP
      port: 5432

Key Security Implementations

1. Pod Security Standards

• Implemented restrictive Pod Security Standards across all PCI-scoped namespaces
• Enforced non-root containers and read-only file systems
• Disabled privilege escalation and host network access

2. Secrets Management

• Integrated AWS Secrets Manager with EKS using IAM roles for service accounts
• Implemented automatic secret rotation for database credentials
• Used sealed secrets for Kubernetes-native secret management

3. Container Image Security

• Established secure CI/CD pipeline with vulnerability scanning
• Implemented admission controllers to prevent vulnerable images
• Used minimal base images and multi-stage builds

Compliance Framework Implementation

Requirement 1 & 2: Firewall and Security Configuration

We implemented a comprehensive firewall strategy using AWS Security Groups, NACLs, and Kubernetes Network Policies:

# Security Group for EKS Worker Nodes
resource "aws_security_group" "eks_pci_workers" {
  name_prefix = "eks-pci-workers"
  vpc_id      = var.vpc_id

  # Only allow traffic from ALB
  ingress {
    from_port       = 443
    to_port         = 443
    protocol        = "tcp"
    security_groups = [aws_security_group.alb.id]
  }

  # Allow outbound for package updates (controlled)
  egress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name     = "eks-pci-workers"
    PCIScope = "true"
  }
}

Requirement 3: Cardholder Data Protection

Encryption at every layer was crucial:

• In Transit: TLS 1.3 for all communications, service mesh with mTLS
• At Rest: EBS encryption, EFS encryption, encrypted container images
• In Memory: Application-level encryption for sensitive data processing

Requirement 8: User Access Management

We implemented a robust RBAC system integrated with the client's existing Active Directory:

# PCI Compliance RBAC
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: pci-payment-processor
rules:
- apiGroups: [""]
  resources: ["pods", "services", "configmaps"]
  verbs: ["get", "list", "watch"]
  resourceNames: ["payment-*"]
- apiGroups: ["apps"]
  resources: ["deployments"]
  verbs: ["get", "list", "watch", "update"]
  resourceNames: ["payment-processor"]

Monitoring and Logging: Requirement 10 & 11

Comprehensive Audit Trail

We implemented a multi-layered logging strategy:

1. Cluster-Level Logging

• EKS control plane logs sent to CloudWatch
• Audit logs for all API server interactions
• Node-level logs for system events

2. Application-Level Logging

• Structured logging for all payment transactions
• Correlation IDs for end-to-end tracing
• Real-time log analysis and alerting

3. Security Monitoring

• Integration with STAQI's 24/7 SOC
• Real-time threat detection using AWS GuardDuty
• Custom security rules for PCI-specific threats

Monitoring Architecture

# Prometheus ServiceMonitor for Payment Services
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: payment-processor-metrics
  namespace: monitoring
spec:
  selector:
    matchLabels:
      app: payment-processor
  endpoints:
  - port: metrics
    interval: 30s
    path: /metrics

Results: Performance Meets Compliance

Quantifiable Improvements

Performance Gains:

• 40% reduction in transaction processing latency
• 99.99% uptime (improved from 99.9%)
• 60% faster deployment cycles
• Auto-scaling capabilities handling 5x traffic spikes

Compliance Achievements:

• Successful PCI DSS Level 1 certification
• 100% audit compliance across all requirements
• Reduced compliance scope by 70% through proper segmentation
• Automated compliance reporting and monitoring

Operational Benefits:

• 50% reduction in operational overhead
• Automated security patching and updates
• Self-healing infrastructure capabilities
• Enhanced disaster recovery with cross-region replication

Lessons Learned: Best Practices for PCI on EKS

1. Start with Security Architecture

Don't bolt on security later. Design your EKS cluster with PCI DSS requirements from day one:

• Network segmentation strategy
• Encryption everywhere approach
• Principle of least privilege access

2. Automate Compliance Monitoring

Manual compliance checking doesn't scale:

• Implement policy-as-code using tools like OPA Gatekeeper
• Continuous compliance monitoring and alerting
• Automated remediation where possible

3. Documentation is Critical

PCI DSS requires extensive documentation:

• Maintain architecture diagrams and data flow documentation
• Automate compliance evidence collection
• Regular compliance training for development teams

The STAQI Advantage: Why This Succeeded

This project's success wasn't just about technical implementation—it was about bringing together deep expertise in:

• High-Volume Transaction Processing: Our experience with millions of daily transactions
• Enterprise Security: Our SOC operations and security monitoring capabilities
• Compliance Expertise: Our practical knowledge of PCI DSS requirements
• 24/7 Operations: Our round-the-clock monitoring and support

Looking Forward: Continuous Improvement

Compliance isn't a one-time achievement. We continue to work with this client on:

• Quarterly compliance assessments
• Security updates and patch management
• Performance optimization and scaling
• Integration of new payment methods and technologies

The journey to PCI DSS compliance on Amazon EKS is complex, but with the right architecture, implementation, and ongoing support, it's absolutely achievable while maintaining the performance and scalability benefits of cloud-native infrastructure.

Ready to modernize your payment infrastructure while maintaining compliance? Contact STAQI Technologies to learn how we can help your organization achieve similar results.