Paper 2021/058

A Performance Study of Crypto-Hardware in the Low-end IoT

Peter Kietzmann and Lena Boeckmann and Leandro Lanzieri and Thomas C. Schmidt and Matthias Wählisch

Abstract

In this paper, we contribute a comprehensive resource analysis for widely used cryptographic primitives across different off-the-shelf IoT platforms, and quantify the performance impact of crypto-hardware. This work builds on the newly designed crypto-subsystem of the IoT operating system RIOT, which provides seamless crypto support across software and hardware components. Our evaluations show that (i) hardware-based crypto outperforms software by considerably over 100 %, which is crucial for nodal lifetime. Despite, the memory consumption typically increases moderately. (ii) Hardware diversity, driver design, and software implementations heavily impact resource efficiency. (iii) External crypto-chips operate slowly on symmetric crypto-operations, but provide secure write-only memory for private credentials, which is unavailable on many platforms.