A Study for Low Calculation Cost Side-Channel Resistance Prediction Based on Transfer Impedance of Leakage Path

We investigated the possibility of low-cost prediction of side-channel attack (SCA) vulnerability without the need to observe a large number of leakage traces for application to the side-channel attack countermeasure design for cryptographic devices. Assuming an on-board power analysis attack against the Advanced Encryption Standard (AES), we applied a decoupling capacitor as a countermeasure against SCA on the printed circuit board. The leakage strength after the countermeasure was predicted from the change in the transfer impedance of the leakage path due to the addition of the capacitor. As a result, the prediction agreed with the measured leakage strength for a limited decoupling configuration. This result suggests that it is necessary to improve the method of estimating the effect of the transfer impedance on the leakage strength to predict the SCA resistance of cryptographic devices quantitatively without observing the leakage traces.