Design Space Exploration for Ultra-Low-Energy and Secure IoT MCUs

Abstract

This article explores the design space of secure communication in ultra-low-energy IoT devices based on Micro-Controller Units (MCUs). It tries to identify, benchmark, and compare security-related design choices in a Commercial-Off-The-Shelf (COTS) embedded IoT system which contributes to the energy consumption. We conduct a study over a large group of software crypto algorithms: symmetric, stream, hash, AEAD, MAC, digital signature, and key exchange. A comprehensive report of the targeted optimization attributes (memory, performance, and specifically energy) will be presented from over 450 experiments and 170 different crypto source codes. The article also briefly explores a few system-related choices which can affect the energy consumption of secure communication, namely, architecture choice, communication bandwidth, signal strength, and processor frequency. In the end, the article gives an overview of the obtained results and the contribution of all. Finally, it shows, in a case study, how the results could be utilized to have a secure communication in an exemplary IoT device. This article gives IoT designers insight into ultra-low-energy security, helps them to choose appropriate cryptographic algorithms, reduce trial-and-error of alternatives, save effort, and hence cut the design costs.