The Zero Trust Principle: Never Trust, Always Verify
The traditional perimeter security model assumed that everything inside the corporate firewall was trusted. Once an attacker gained access to the internal network — via phishing, VPN credential theft, or physical access — they could move laterally with minimal friction. Zero Trust Architecture (ZTA) rejects this assumption entirely. The foundational principle, articulated by John Kindervag at Forrester in 2010 and codified by NIST in Special Publication 800-207 (2020), is: no user, device, or network location is inherently trusted. Every access request must be authenticated, authorized, and continuously validated regardless of source.