Measurement and Analysis of Electromagnetic Information Leakage from Printed Circuit Board Power Delivery Network of Cryptographic Devices

This article presents a novel measurement and analysis of electromagnetic (EM) information leakage from printed circuit board (PCB) power delivery network (PDN) of cryptographic devices. We propose an accurate EM information leakage analysis method based on a correlation electromagnetic analysis (CEMA) considering advanced encryption standard (AES) operation cycles and clock frequency. We measure field distribution on the PCB level AES core PDN and conduct the proposed analysis method to derive the information leakage maps. For the first time, we verified that the EM information leakage depends on the intensity of dominant field distribution on the PCB PDN using the proposed method. We validated that the whole secret key information can be extracted from locations in the PCB PDN distant from the cryptographic integrated circuit where a specific field is dominant due to the physical structure of the PCB PDN. Based on the measurement and analysis results, we discuss an efficient EM information leakage evaluation method based on the dominant field radiation. We evaluate the EM information leakage from the decoupling capacitor in the backside of the PCB. Finally, we propose a design methodology to suppress the EM information leakage from the PCB PDN.