A Fast Transient Response Distributed Power Supply With Dynamic Output Switching for Power Side-Channel Attack Mitigation

Abstract

We present a distributed power supply and explore its load transient response and power side-channel security improvements. Typically, countermeasures against power side-channel attacks (PSCAs) are based on specialized dc/dc converters, resulting in large power and area overheads and they are difficult to scale. Moreover, due to limited output voltage range and load regulation, it is not feasible to directly distribute these converters in multicore applications. Targeting those issues, our proposed converter is designed to provide multiple fast-responding voltages and use shared circuits to mitigate PSCAs. The proposed three-output dc/dc converter can deliver 0.33–0.92 V with up to 1 A to each load. Comparing with state-of-the-art power management works, our converter has $2\times $ load step response speed and $4\times $ reference voltage tracking speed. Furthermore, the converter requires $9\times $ less inductance and $3\times $ less output capacitance. In terms of PSCA mitigation, this converter reduces the correlation between input power trace and encryption load current by $107\times $ , which is $3\times $ better than the best standalone work, and it only induces 1.7% area overhead and 2.5% power overhead. The proposed work also increases minimum traces to disclose (MTDs) by $1250\times $ . Considering all the above, our work could be a great candidate to be employed in future multicore systems supplying varying voltages and resisting side-channel attacks. It is the first work bridging the gap between on-chip power management and side-channel security.