Zero Trust Architecture & The Passkey Paradigm: The End of Perimeter Security & Modern Cryptographic Identity

For decades, enterprise IT relied on the castle-and-moat perimeter model, trusting any entity inside the corporate VPN. Modern remote work, hybrid clouds, and advanced supply-chain phishing have shattered this perimeter, giving rise to NIST SP 800-207 Zero Trust Architecture: "Never Trust, Always Verify."

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▶ 1. NIST SP 800-207 Core Architecture

Zero Trust separates operations into a Control Plane (Policy Engine + Policy Administrator as Policy Decision Point) and Data Plane (Policy Enforcement Points), enforcing context-aware access decisions across identity, device health, location, and telemetry.

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▶ 2. The Passkey (FIDO2/WebAuthn) Paradigm

Passkeys eliminate shared secrets using asymmetric public-key cryptography:

Private keys ($K_{priv}$) remain locked within hardware Secure Enclaves / TPM chips.

Origin-bound challenge signatures mathematically prevent credential stuffing and MitM reverse-proxy phishing.

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▶ 3. Workload Identity & Service Mesh mTLS

Inter-service communication is secured via SPIFFE IDs and short-lived X.509 SVID certificates rotated by SPIRE, with Envoy sidecar proxies executing continuous mutual TLS (mTLS) microsegmentation.