Lightweight Fault-Resilient KLEIN Cipher for IoT Encryption

Abstract

The KLEIN lightweight block cipher provides an effective encryption method suitable for IoT devices with limited computational resources, memory, and energy capacity. Despite its efficiency, the compact design of KLEIN is vulnerable to fault injection attacks, which can disrupt encryption and compromise data security. In this study, we propose a comprehensive fault detection and correction framework for KLEIN that combines parity verification, cyclic redundancy checks (CRC), and a Secure Rollback Recovery mechanism with deceptive output. This approach enables real-time fault identification, produces misleading ciphertext to thwart attackers, and restores the system to the last known correct state, ensuring uninterrupted and reliable encryption. The framework was implemented on an FPGA using Vivado 2022 and validated under various fault scenarios. Results show that the design achieves high fault coverage while maintaining efficiency, with only a 1.73% reduction in operating frequency for detection, a 1.13% hardware overhead for fault detection and a 66.28% increase in hardware area for correction. Overall, the proposed solution significantly strengthens KLEIN against fault injection threats, providing a secure and lightweight cryptographic option for resource-constrained IoT applications.