In this paper, we propose a novel approach that utilizes localized X-ray irradiation to amplify data-dependent leakage currents in CMOS-based cryptography circuits. Our proposed technique strategically targets specific regions in a circuit using X-rays, inducing variations in dynamic and static power consumption due to Total Ionizing Dose (TID) effects, which increases or even reveals hidden data leakage. In this work, we present several experimental campaigns highlighting the benefits of our approach to combinational and sequential logic. Our experiments show a significant increase in information leakage in the targeted regions, which improves the signal-to-noise ratio coefficient and thus makes recovering the processed bytes easier. We envision the possibility of using this technique on full cryptographic designs on both FPGA and ASICs.

International audience

Although multi-fault attacks are extremely powerful in defeating sophisticated hardware and software defences, detecting and exploiting such attacks remains a difficult problem, especially without any prior knowledge of the target. Our main contribution is an end-to-end approach for multi-fault attack vulnerability assessment We take advantage of target specific fault models rather than generic fault models to achieve complex multi-fault attacks that can lead to critical vulnerabilities. Target specific fault models are generated thanks to fault models inference process, based on a fault injections simulation and a characterization, in order to elaborate powerful multi-fault attacks based on different fault models. Combining fault models opens up new possible attack paths and adds flexibility to design fault attacks that adapt to countermeasures. Hence, the direct consequence of the increasing complexity of fault attacks question the effectiveness of software countermeasures based on generic fault models for sensitive applications.