In-depth Analysis of the Effects of Electromagnetic Fault Injection Attack on a 32-bit MCU

As semiconductor technology developing, current microcontrollers (MCUs) contain processor, memory, bus and peripherals, and become a low-power system-on-chip platform supporting various IoT applications. Although providing powerful real-time process capability, MCUs are vulnerable to fault injection attacks (FIAs) which target at the valuable data such as cipher key and personal information. While many research studies concentrated on successful FIAs on MCUs, this paper focuses on the low-cost and high-efficiency FIA technique, electromagnetic fault injection (EMFI), and its effects on the very widespread MCU (STM32F103ZET6) with ARM 32-bit Cortex™-M3 kernel. Interestingly, we observe a number of faults which consistently occur, such as the USART interface errors and the computation errors. By characterizing and reasoning the faults, we identify the vulnerabilities of the MCU and the EMPI fault models. Finally, countermeasures against the EMPI attacks are recommended.