Paper 2020/218

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

Ehsan Aerabi, Milad Bohlouli, MohammadHasan Ahmadi Livany, Mahdi Fazeli, Athanasios Papadimitriou, and David Hely

Abstract

This paper explores the design space of secure communication in ultra-low-energy IoT devices based on Micro-Controller Units (MCUs). It tries to identify, evaluate and compare security-related design choices in a Commercial-Off-The-Shelf (COTS) embedded IoT system which contribute in the energy consumption. We conduct a study over a large group of software-implemented 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 paper 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 paper gives an overview on 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 paper gives IoT designers an insight on the 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.