An Anti-Physical Attack Scheme of ARX Lightweight Algorithms for IoT Applications

Abstract

The lightweight encryption algorithm based on Add-Rotation-XOR (ARX) operation has attracted much attention due to its high software affinity and fast operation speed. However, lacking an effective defense scheme for physical attacks limits the applications of the ARX algorithm. The critical challenge is how to weaken the direct dependence between the physical information and the secret key of the algorithm at a low cost. This study attempts to explore how to improve its physical security in practical application scenarios by analyzing the masking countermeasures of ARX algorithms and the leakage causes. Firstly, we specify a hierarchical security framework by quantitatively evaluating the indicators based on side-channel attacks. Then, optimize the masking algorithm to achieve a trade-off balance by leveraging the software-based local masking strategies and non-full-round masking strategies. Finally, refactor the assembly instruction to improve the leaks by exploring the leakage cause at assembly instruction. To illustrate the feasibility of the proposed scheme, we further conducted a case study by designing a software-based masking method for Chaskey. The experimental results show that the proposed method can effectively weaken the impact of physical attacks.