Run-time Monitoring and Validation using Reverse Function (RMVRF) for Hardware Trojans Detection

There has recently been a significant growth in resource-constrained devices (RCDs) that exchange sensitive and private data. Lightweight ciphers are designed to implement confidentiality in RCDs. Hardware implementation of lightweight cipher should minimize resources, including area, power and energy. Hardware Trojans (HTs) are malicious circuits that are inserted into designs, including lightweight ciphers, to modify cipher behavior and leak sensitive data. Although runtime monitoring is a very effective method to implement design-for-trust and detect hardware Trojans, it requires significant resources and degrades performance. The main motivation of this research is to design RCD-friendly runtime monitoring and create a trusted design with minimal resource overhead. This paper develops a low-power, low-energy and trusted design based on a smart runtime monitoring algorithm targeted for lightweight ciphers in RCDs, implemented in the FPGA platform. The algorithm is adaptive, minimizes resource, and maximizes confidence and HT detection. The novelties of the algorithm are its adaptive activation of checking and its validation. Checking is triggered when a predefined critical node is active, which limits power/energy overhead. Our proposed algorithm has adaptive positive aging because it forgoes validation when a critical node has been already proven safe. To optimize trust, the validation uses a reverse-function design. The implementation results show that proposed algorithm reduces area, power and energy, when compared with existing algorithms. The proposed algorithm achieves 37%-55% reduction in energy and power, and has an average of 53% improvement in LE×energy metric. Furthermore, our proposed algorithm reduces the area by 25% when both encryption and decryptions are implemented.