EM Attack Is Non-Invasive?- Design Methodology and Validity Verication of EM Attack Sensor

Abstract. This paper presents a standard-cell-based semi-automatic design methodology of a new conceptual countermeasure against elec-tromagnetic (EM) analysis and fault-injection attacks. The countermea-sure namely EM attack sensor utilizes LC oscillators which detect vari-ations in the EM field around a cryptographic LSI caused by a mi-cro probe brought near the LSI. A dual-coil sensor architecture with an LUT-programming-based digital calibration can prevent a variety of microprobe-based EM attacks that cannot be thwarted by conven-tional countermeasures. All components of the sensor core are semi-automatically designed by standard EDA tools with a fully-digital stan-dard cell library and hence minimum design cost. This sensor can be therefore scaled together with the cryptographic LSI to be protected. The sensor prototype is designed based on the proposed methodology together with a 128bit-key composite AES processor in 0.18m CMOS with overheads of only 2 % in area, 9 % in power, and 0.2 % in performance, respectively. The validity against a variety of EM attack scenarios has been verified successfully.