Xoodyak Under SCA Siege

In this paper, we conduct a detailed power side-channel analysis of Xoodyak, a lightweight cryptographic algorithm, on an FPGA platform. We focus on the initialization phase of Xoodyak in the authenticated encryption with associated data (AEAD) mode. First, we introduce a new leakage model and perform a leakage assessment. Then, we perform non-profiled and profiled attacks to determine if the observed leakages can be exploited. For a non-profiled attack, we perform a correlation power analysis on all key bits, achieving a success rate of 91.4% with 50 000 traces. Our approach for a profiled attack involves a template attack and a deep learning-based attack. The former achieves a success rate of 99.2%, recovering almost all key bits with 20 000 traces in the attack phase. The latter reaches a guessing entropy of zero after 550 traces and adapts to the leakage model within 50 epochs.