Refinement and Empirical Side-Channel Analysis of Inner Product Masking with Robust Error Detection

Side-channel attacks represent a significant and persistent threat to hardware security. One effective strategy for safeguarding hardware components against these attacks involves the implementation of masking schemes. Among these schemes, Inner Product Masking (IPM) has received considerable attention and analysis in prior research. Inner Product Masking with Error Detection aims to extend the security provided by IPM to Fault-Injection attacks. This can be achieved by incorporating (linear) repetition code for fault detection (IPM-FD) or by integrating a non-linear robust error detection into the scheme (IPM-RED). IPM-RED can detect (with non-zero probability) every fault regardless the number of bits it flips. However, this robustness comes with a cost, a non-linear function may leak via the physical channels more information than a linear one. This paper shows that information leakage from IPM-RED is marginal. An improved IPM-RED masking scheme is also presented, and an empirical side-channel leakage analysis of the protected Advanced Encryption Standard (AES) design utilizing the Test Vector Leakage Assessment (TVLA).