Horizontal Attack Against EC kP Accelerator Under Laser Illumination

Devices employing cryptographic approaches have to be resistant to physical attacks. Side-Channel Analysis (SCA) and Fault Injection (FI) attacks are frequently used to reveal cryptographic keys. In this paper, we present a combined SCA and laser illumination attack against an Elliptic Curve Scalar Multiplication accelerator, while using different equipment for the measurement of its power traces, i.e., we performed the measurements using a current probe from Riscure and a differential probe from Teledyne LeCroy, with an attack success of 70% and 90%, respectively. Our experiments showed that laser illumination increased the power consumption of the chip, especially its static power consumption, but the success of the horizontal power analysis attacks changed insignificantly. After applying 100% of the laser beam output power and illuminating the smallest area of 143 µm2, we observed an offset of 17 mV in the measured trace. We assume that using a laser with a high laser beam power, as well as concentrating on measuring and analysing only static current, can significantly improve the attack’s success. The attacks exploiting the Static Current under Laser Illumination (SCuLI attacks) are novel, and their potential has not yet been fully investigated. These attacks can be especially dangerous against cryptographic chips manufactured in downscaling technologies. If such attacks are feasible, appropriate countermeasures have to be proposed in the future.