EM/Power Side-Channel Attack: White-Box Modeling & Signature Attenuation Countermeasures

The requirement of advanced security mechanisms is of utmost importance in today’s internet-connected devices. Although most embedded devices today employ computationally-secure encryption engines for data confidentiality, recent real-world attacks have exploited side-channel information from the power consumption or even the electromagnetic (EM) radiation to extract the secret key operating in the device. Traditional approaches to EM/power side-channel analysis (SCA) countermeasures include gate-level masking, power balancing, noise injection, and supply isolation techniques which include switched capacitor current equalizer, digital low dropout (LDO) regulators, and buck converters. However, most of these countermeasures incur high power, performance, and area overheads (> 2×), or involve modifying the algorithm, architecture, or logic design of the crypto engines. This article analyzes a white-box modeling of the EM leakage from a crypto IC, leading to a low-overhead current domain signature attenuation (CDSA) hardware design with local low-level metal routing to prevent against both EM as well as power SCA attacks. We analyze the evolution of the CDSA design and its long-term impact, along with future research directions in the form of a synthesizable and technology-scalable signature suppression based EM and power SCA countermeasure.