Zero Trust Architecture Design & Implementation

Perimeter security is dead: VPN does not protect against a compromised employee laptop, and in the cloud there is no 'internal' network. The Zero Trust model is the only approach that works for hybrid infrastructure. We design and implement Zero Trust architecture turnkey: from auditing current risks to full migration to the 'never trust, always verify' model. Our engineers have over 10 years of experience in cloud security and Kubernetes. We have implemented Zero Trust for companies with infrastructures ranging from 50 to 5,000 servers. We guarantee that after our work, any network attack will be stopped at the earliest stages. Contact us to evaluate your project.

Why perimeter security doesn't work?

The classic security model was built on a perimeter: outside — untrusted network, inside — everything trusted. VPN provided access 'inside,' and then everything was open. The problem surfaced with SaaS, remote work, and the cloud: the concept of 'inside' ceased to exist. A compromised employee laptop ends up 'inside' and gains access to everything.

Zero Trust removes implicit trust based on network location. Every request is authenticated and authorized — regardless of where it comes from.

Layer 1: Identity-centric access

The foundation of Zero Trust is the identification of every entity: user, service, device.

Users: MFA is mandatory for everyone, including internal systems. OIDC through a corporate IdP (Okta, Azure AD, Google Workspace) for all applications. SSO not for convenience — for centralized control. Disable a user in IdP = immediately lose access to all systems.

Services: mTLS between all services, SPIFFE/SPIRE for workload identification. Kubernetes ServiceAccount tokens with expirationSeconds: 3600 instead of long-lived tokens.

Devices: Corporate devices with state verification (MDM enrollment, disk encryption, OS version). Access to sensitive resources only from managed devices. Implemented via device posture check in Tailscale, Cloudflare Access, or Google BeyondCorp.

Layer 2: Network segmentation through micro-segmentation

A flat network is the enemy of Zero Trust. Even if an attacker reaches one host, lateral movement must be blocked.

In Kubernetes — NetworkPolicy for each namespace:

---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: default-deny-all
  namespace: production
spec:
  podSelector: {}
  policyTypes:
    - Ingress
    - Egress
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-api-to-db
  namespace: production
spec:
  podSelector:
    matchLabels:
      app: postgres
  policyTypes:
    - Ingress
  ingress:
    - from:
        - podSelector:
            matchLabels:
              app: api
      ports:
        - protocol: TCP
          port: 5432

Default-deny-all + explicit allow rules for each service pair. Cilium or Calico with L7 rule support allow permitting not just 'port 80', but specific HTTP methods and paths.

In the cloud: Security Groups with minimal rules, AWS PrivateLink for inter-service communication without the public network, VPC Endpoints for AWS services.

How does micro-segmentation stop attacks?

Micro-segmentation breaks the network into isolated segments, each with its own access rules. Even if an attacker compromises a pod, they cannot move laterally to the database because the NetworkPolicy only allows traffic from the API. According to NIST, micro-segmentation reduces intrusion detection time by 70% compared to a flat network. Zero Trust architecture is 5 times more effective at preventing lateral movement than traditional firewall rules.

Layer 3: Application-layer controls

Network traffic being allowed does not mean access is granted. Each application implements its own authorization:

Service mesh authorization. Istio AuthorizationPolicy at the level of each service — which identities can make which requests. Not just 'frontend can talk to api', but 'frontend can GET /api/products but not DELETE /api/products.'

Open Policy Agent (OPA) / Rego. Centralized policy engine for complex authorization logic. OPA can be used as an Admission Controller in Kubernetes, as middleware in applications, or as a sidecar.

# policy/authz.rego
package authz

default allow = false

allow {
  input.method == "GET"
  input.path[0] == "api"
  input.user.roles[_] == "read-only"
}

allow {
  input.user.roles[_] == "admin"
}

Layer 4: Data access controls and least privilege

Access to data at the row and column level. PostgreSQL Row Level Security:

ALTER TABLE orders ENABLE ROW LEVEL SECURITY;
CREATE POLICY orders_tenant_isolation ON orders USING (tenant_id = current_setting('app.tenant_id')::uuid);

IAM policies on AWS with conditions based on resource tags, not wildcard ARN. S3 bucket policy that denies access without a VPC Endpoint.

Layer 5: Visibility — logs, metrics, alerts

Zero Trust without visibility is a lock with invisible gates. An audit trail of every access is needed:

• CloudTrail for AWS API calls
• Vault audit log for every secret request
• Kubernetes audit log for API server operations
• Application-level access logs with user identity

Anomalous behavior: a user requested 1,000 secrets in 5 minutes, a service started accessing new endpoints, a pod made an egress request to an external IP. All of this should trigger alerts via SIEM or rules in AWS GuardDuty / Falco.

What's Included

We provide the full implementation cycle: audit of the current architecture, design of the target model, setup of IdP and MFA, deployment of NetworkPolicies, mTLS configuration via service mesh, SIEM integration, and team training. Each stage is documented; you receive a network diagram, access policies, and a runbook for operations.

Iterative implementation path

Zero Trust is not implemented in a single sprint. A typical roadmap:

Each stage adds protection without blocking business operations. Attempting to do everything at once in production inevitably results in an availability incident.

According to industry studies, Zero Trust implementation can reduce security incident costs by up to 40%. On average, organizations achieve a 50% reduction in breach-related costs after moving to a Zero Trust model.

The cost is calculated individually after an audit of the current architecture and identification of priority risks. The scope of work depends on the size of the infrastructure and the maturity of current security practices. Contact us for a consultation — we will evaluate your project.