Zero-Trust Security Frameworks for Heterogeneous IoT Networks in Industrial Environments: A Lightweight Continuous-Authentication Protocol

The convergence of Information Technology (IT) and Operational
Technology (OT) in Industry 4.0 smart manufacturing floors introduces
dense, heterogeneous Industrial Internet of Things (IIoT) networks.
Traditional perimeter-based security architectures fail to protect these
networks against lateral threat movement, device cloning, and session
hijacking. While Zero-Trust Architecture (ZTA) enforces the core
principle of “never trust, always verify,” implementing continuous
authentication on resource-constrained, low-power field devices (e.g., 8-
bit/32-bit microcontrollers, wireless sensor nodes, and smart actuators)
introduces prohibitive computational delays and battery depletion. This

paper proposes the Lightweight Continuous PUF-ECC Re-
Authentication Protocol (LCP-RAP) designed specifically for low-
power IIoT field assets. LCP-RAP combines SRAM-based Physical

Unclonable Functions (PUF) for keyless hardware identity generation,
lightweight Elliptic Curve Cryptography over Curve25519, and a
dynamic context-aware trust scoring mechanism. Evaluating 500
heterogeneous IIoT field nodes across a simulated factory testbed over
100,000 continuous communication sessions, empirical results show that
LCP-RAP reduces initial handshake latency by 92.5% (from 245 ms
under X.509 PKI to 18.4 ms) and cuts continuous packet re-verification
time to 1.12 ms. Furthermore, energy consumption is reduced by 74.2%
relative to standard TLS 1.3 setups, consuming less than 3.2% of the
daily power budget of battery-operated field sensors while defending
against 99.8% of impersonation, physical cloning, and replay attacks.