Design and Simulation of an Energy-Efficient Adaptive Lightweight Post-Quantum Cryptographic Framework for Resource-Constrained IoT Devices

The increasing advancement of quantum computing threatens the security foundations of classical public-key cryptosystems, particularly RSA and ECC, which remain widely deployed across IoT infrastructures. However, existing post-quantum cryptographic (PQC) schemes are computationally intensive and often unsuitable for resource-constrained IoT devices where memory, CPU cycles, and battery capacity are severely limited. This work proposes EAL-PQCF, an Energy-Efficient Adaptive Lightweight Post-Quantum Cryptographic Framework explicitly designed for constrained IoT environments. The framework introduces a three-mode adaptive PQC strategy consisting of Eco-Secure, Standard-Secure, and Quantum-Threat modes, each selected dynamically based on device battery level, CPU load, and message sensitivity. A Python-based virtual testbed incorporating a simulated IoT device model, lattice-based PQC primitives, an energy estimation module, and an adaptive decision engine is developed for performance evaluation. Experimental results demonstrate that EAL-PQCF achieves 18–36% energy savings, 14–29% reduction in CPU cycles, and significantly improved battery longevity compared to baseline PQC methods. The proposed solution bridges the gap between high-security quantum-resistant cryptography and the practical constraints of IoT devices, offering a scalable pathway for secure next-generation IoT deployments.