Protection of the Digital Circuitry of a Single-Slope ADC Against Side-Channel Attacks

Analog-to-digital converters are necessary to interpret the continuous world in digitized format, and side-channel attacks on ADCs can reveal such digital data.Single-slope ADCs constitute an important class of devices which require protection, and this work proposes two techniques to resist classification of power traces by Convolutional Neural Networks. The first technique is duplication of toggle detection circuitry together with a dummy register array to mask comparator activity in the power trace.The second technique is to randomize the activation time of the comparator based on a secondary ramp signal with a dynamically varying slope. Both techniques reduce classification accuracy of all digital bits to near random guessing, with the first performing slightly better with lower area overhead.