IoT-enabled smart home devices communicating through protocols like BLE or Zigbee, often constrained by limited computational resources and lack of direct internet connectivity, face significant authentication challenges. Traditional cryptographic methods such as Public-Key Infrastructure (PKI) or Identity-Based Encryption (IBE) impose heavy computational overheads, making them unsuitable for resource-constrained IoT environments. To address these issues, we propose a novel lightweight authentication protocol leveraging Physical Unclonable Functions (PUFs), utilizing smart-phones as intermediaries to facilitate secure communication with a trusted server. Our scheme avoids the overhead of maintaining large Challenge-Response Pair (CRP) databases and eliminates complex operations like Elliptic Curve cryptography and digital certificates (X.509). Experiments on an ESP32-based testbed demonstrate significant efficiency improvements over existing protocols, confirming the practicality of our lightweight approach for resource-constrained IoT environments.

This paper proposes a novel security framework that integrates Logic locking with intrinsic SRAM PUFs for simultaneous user authorization and hardware authentication. By leveraging stable SRAM cell responses, the approach eliminates external key storage, deriving unlocking keys through a structured transformation process. Experimental validation on ESP32 devices demonstrates high intra-device response consistency and distinct inter-device signatures. This unified mechanism ensures that only authorized users can access the system and only authenticated ICs can function, mitigating risks of overproduction and external attacks. The results establish SRAM PUFs as a lightweight, efficient, and tamper-resistant solution for secure key derivation.