Efficient Electromagnetic Analysis Based on Side-channel Measurement Focusing on Physical Structures

In this paper, we study on improving efficiency of the electromagnetic analysis (EMA) based on side-channel measurement for revealing a secret key inside the cryptographic module. In this study, we focus on the specific physical structures of the printed circuit board (PCB) near the cryptographic module and conducted the EMA where the distribution of electric or magnetic field containing the secret key information is dominant. Based on the experimental results, we validated that the whole secret key information can be efficiently extracted by conducting the EMA using a single electric or magnetic probe on the location where a specific field is dominant due to the physical structure. By analyzing the physical structure of the PCB including the cryptographic module and considering the dominant field, the secret key information from the cryptographic module can be efficiently extracted.