Information Leakage Through Physical Layer Supply Voltage Coupling Vulnerability

Power side-channel attacks are widely known for extracting information from data processed within a device while assuming that an attacker has physical access or the ability to modify the device. In this article, we introduce a novel side-channel vulnerability that leaks data-dependent power variations through physical layer supply voltage coupling (PSVC). Unlike traditional power side-channel attacks, the proposed vulnerability allows an adversary to mount an attack and extract information without modifying the device. In addition, unlike existing power-based remote attacks on field-programmable gate arrays (FPGAs), the PSVC vulnerability applies to both on-chip and on-board attacks. We assess the effectiveness of the PSVC vulnerability through three case studies, demonstrating several end-to-end attacks on general-purpose microcontrollers with varying adversary capabilities. These case studies provide evidence for the existence of the PSVC vulnerability, its applicability to on-chip as well as on-board side-channel attacks, and how it can eliminate the need for physical access to the target device, making it applicable to any off-the-shelf hardware. Our experiments also reveal that designing devices to operate at the lowest operational voltage significantly reduces the risk of PSVC side-channel vulnerability.