Improving Side-channel Leakage Assessment Using Pre-silicon Leakage Models

Side-channel leakage assessment is an essential tool in the security evaluation of new chip designs. Pre-silicon side-channel analysis tools have made significant progress in delivering assessment results early in the chip design flow. However, a gap remains with actual implementations where measurements are affected by noise and distortions. These measurement imperfections degrade the assessment of the physical prototype and may lead to false negatives. In this contribution, we present a transfer learning technique to improve the assessment of physical prototypes using pre-silicon side-channel leakage simulation of the same implementation. The noiseless simulation traces are used for initial profiling to train a convolutional neural network (CNN). The trained CNN is then used in the assessment of measured traces. We apply this idea to Ascon and Xoodyak, two different sponge-based cryptographic primitives proposed in the NIST Lightweight Crypto competition. The target platform is a software implementation on a RISC-V (RV32IMC) microcontroller realized using 180nm CMOS technology. Side-channel leakage is first captured using gate-level power simulation and then measured from a chip prototype of the same design. We investigate different side-channel analysis strategies under simulated and measured scenarios and demonstrate that, in each case, machine-learning-based side-channel leakage assessment outperforms other profiled and non-profiled analysis. However, using the proposed transfer learning technique, we can improve the side-channel leakage assessment even further. With the proposed transfer learning technique, we need approximately 2.87 less measured traces compared to the previous best profiled attack. We conclude that the proposed transfer learning using pre-silicon leakage models can improve the side channel leakage assessment of post-silicon implementations.