A Random Interrupt Dithering SAR Technique for Secure ADC Against Reference-Charge Side-Channel Attack

Abstract

A side-channel attack (SCA) on a reference-charge flow in successive approximation register (SAR) analog-to-digital converters (ADCs) discloses analog information acquired at a sensor frontend. A random interrupt dithering masks the correlation between analog input and reference charge flow by injecting extremely large dither of 1/4 full scale. An internal dither-tracking comparator yet guarantees rail-to-rail operation, resulting in no penalty in conversion accuracy. The comparator functions as a physical-random source for dithering. The unpredictable randomness based on comparator metastable operation by thermal noise enhances the security level while the shared use of the comparator reduces the associated hardware overhead. The additional silicon area penalty for the proposed technique is only 7% of an unprotected ADC core area. A 10-bit 1 MS/s secure SAR ADC was fabricated in 0.18-µm CMOS. The measurement results demonstrate the proposed secure ADC suppresses the information leakage from 4.6 bit to 0.8 bit against reference-charge SCA.

An Analog Side-Channel Attack on a High-Speed Asynchronous SAR ADC Using Dual Neural Network Technique

“…3 compares the SCA methods of the conventional template/NN based attacks and proposed Dual-NN based attack. The conventional methods reported in [7] and [10] acquire noise waveforms of 𝑉 DD or 𝑉 REF which indicate the input-dependent activities of the CDAC and comparator inside the ADC, and then construct the template or NN as shown in Fig. 3 (a).…”

“…Successive approximation register (SAR) ADCs are widely used for analog frontend of distributed sensor nodes to benefit from their potential characteristics of small size and low power consumption. The first SCA attempts on ADCs were demonstrated in [7]. It discloses an analog input voltage estimation utilizing reference noise caused by the charge redistribution operation of capacitive digital-toanalog converter (CDAC) in the single-ended SAR ADCs.…”

Dynamical analysis of a new chaotic system and its application in ADC

“…An Analog-to-Digital Converter (ADC) is an electronic component that converts analogue signals in nature into digital signals [1][2][3]. ADC is widely used in key fields such as communication, aerospace, radio observation and medical treatment [4,5]. However, in practice, various nonideal factors [6] such as the capacitance offset, coherent sampling, and clock jitter [7,8] seriously deteriorate the dynamic performance of the ADC [9].…”

Measurement of electromagnetic field immunity of voltage-controlled oscillator-based analog-to-digital converters in 28 nm CMOS technology

“…[18][19][20][21][22] The adoption of IoT applications has been launched for the sake of a small form factor and high energy efficiency. Additional features include the high tolerance to unexpected interactions with the surrounding EM environment, which can happen inevitably or even intentionally, in a passive 23) or active 24) manner. Those circuits need to be designed with the awareness of undesired EM interactions, and might also be embedded with the in-place detection of unexpected disturbance 25) The baseline knowledge to accomplish the goal will be provided mainly through a variety of experimental explorations as what is addressed in this paper.…”