关键词: 密码芯片, 近场, 电磁辐射, 差分电磁分析, 高级加密标准, 现场可编程门阵列

Abstract: To do research for physical information leaked by Electromagnetic（EM） radiations from Field Programmable Gate Arrays（FPGA） cipher chip during its operation, this paper analyzes the principle of direct electromagnetic emanations for Complementary Metal-Oxide-Semiconductor（CMOS） circuit, and then a near-?eld leakage model about FPGA is designed. According to this model, the technique, EM scanning, is used to tackle the problem of the localization of the spatial position of the crypto-processor, in putting an electricmagnetic near-?eld sensor above the chip. Moreover, Advanced Encryption Standard（AES） circuit is completed based on FPGA cryptosystem and Differential ElectroMagnetic Analysis（DEMA） is introduced. As a result, practical experiment has shown that an attacker can extract the secret 128-bit key using 42000 traces of AES cryptographic device under the condition of having localized the optimal leaking spots characterized by mostly data-dependent EM emissions.

Key words: cipher chip, near-field, Electromagnetic（EM） radiations, Differential ElectroMagnetic Analysis（DEMA）, Advanced Encryption Standard（AES）, Field Programmable Gate Arrays（FPGA）