Zero Trust Architecture: Security for the Post-Perimeter Era

The castle-and-moat security model is dead. In a world of remote work and cloud infrastructure, there is no perimeter to defend.

The castle-and-moat security model is dead. In a world of remote work, cloud infrastructure, and API-first architectures, there is no perimeter to defend. Welcome to Zero Trust.

The Core Principle

Zero Trust can be summarized in one phrase:

Never trust, always verify.

Every request, every user, every device is treated as potentially hostile—even if it comes from inside your network.

The Implementation Layers

Identity: Strong authentication (MFA, passkeys, SSO)
Device: Device health checks and attestation
Network: Micro-segmentation and encrypted tunnels
Application: Per-request authorization and audit logging
Data: Encryption at rest and in transit, row-level access

Practical Implementation: Row-Level Security

In Supabase/PostgreSQL, Zero Trust translates to RLS policies:

-- Users can only see their own data
CREATE POLICY "users_own_data" ON documents
  FOR ALL
  USING (auth.uid() = user_id);

-- Admins can see everything
CREATE POLICY "admin_full_access" ON documents
  FOR ALL
  USING (
    EXISTS (
      SELECT 1 FROM user_roles
      WHERE user_id = auth.uid()
      AND role = 'admin'
    )
  );

The Authentication Stack

Factor	What You Know	What You Have	What You Are
Example	Password	Phone, Security Key	Fingerprint, Face
Strength	Weak	Strong	Very Strong

The Takeaway

Security is not a feature—it is an architecture. Build it into every layer, verify at every step, and assume breach. The question is not if you will be attacked, but whether you will notice.