Low-Power IoT Communication Security: On the Performance of DTLS and TLS 1.3

TL;DR

This paper compares the performance of DTLS 1.3 and TLS 1.3 protocols on low-power IoT devices, revealing that newer protocols can be efficient and sometimes even reduce resource use, with room for further optimization.

Contribution

First experimental performance comparison of DTLS 1.3 and TLS 1.3 implementations on real low-power IoT devices, analyzing resource consumption and efficiency.

Findings

DTLS/TLS 1.3 can have comparable or reduced overhead compared to 1.2.

Different implementations impact resource use and performance.

There is potential to optimize protocol implementations for IoT devices.

Abstract

Similarly to elsewhere on the Internet, practical security in the Internet of Things (IoT) is achieved by combining an array of mechanisms, at work at all layers of the protocol stack, in system software, and in hardware. Standard protocols such as Datagram Transport Layer Security (DTLS 1.2) and Transport Layer Security (TLS 1.2) are often recommended to secure communications to/from IoT devices. Recently, the TLS 1.3 standard was released and DTLS 1.3 is in the final stages of standardization. In this paper, we give an overview of version 1.3 of these protocols, and we provide the first experimental comparative performance analysis of different implementations and various configurations of these protocols, on real IoT devices based on low-power microcontrollers. We show how different implementations lead to different compromises. We measure and compare bytes-over-the-air, memory footprint, and energy consumption. We show that, when DTLS/TLS 1.3 requires more resources than DTLS/TLS 1.2, this additional overhead is quite reasonable. We also observe that, in some configurations, DTLS/TLS 1.3 actually decreases overhead and resource consumption. All in all, our study indicates that there is still room to optimize the existing implementations of these protocols.