The 'Never Trust' Model Auditing Zero Trust Architecture (ZTA)
Introduction Traditional network security operated on the 'Castle-and-Moat' model—a hardened perimeter protecting a trusted interior. Organizations invested heavily in firewalls, intrusion prevention systems, and DMZs to keep adversaries outside the network while assuming that users and systems inside the perimeter could be trusted. This model has become fundamentally obsolete in the modern threat landscape. Sophisticated adversaries routinely bypass perimeter defenses through phishing attacks, exploiting remote access vulnerabilities, or compromising supply chain partners. Cloud computing, mobile workforces, and bring-your-own-device (BYOD) policies have dissolved the traditional network boundary. Zero Trust Architecture (ZTA) represents a paradigm shift in security thinking, operating on the principle 'never trust, always verify.' Rather than assuming internal networks are safe, ZTA treats every access request as potentially hostile, requiring continuous authenticat...