Multiplicative Masked M&M: An Attempt at Combined Countermeasures with Reduced Randomness

With the advancement of hardware security, combined attacks with techniques such as side-channel analysis (SCA) and fault analysis (FA) have prompted the development of combined countermeasures. However, these countermeasures often come with significant overhead. In this paper, we explore a solution to reduce the randomness requirement while maintaining security claims. We demonstrate the approach with Mask & Macs (M&M), a scheme that combines Boolean masking and MAC tag redundancy to provide SCA and DFA protection, addressing the challenge of high randomness requirement. We introduce a novel multiplicative masking scheme as a replacement for threshold implementation (TI) modules partially, leading to a reduction of over 50% in randomness requirement with minor increased FPGA resource overhead and latency. While the trade-off is beneficial, other limitations remain, and further research is needed to address these problems. This work provides a new perspective on improving combined countermeasures by exploring ways to reduce system overhead.