Paper 2025/563

An Optimized Instantiation of Post-Quantum MQTT protocol on 8-bit AVR Sensor Nodes

YoungBeom Kim, Kookmin University
Seog Chung Seo, Kookmin University
Abstract

Since the selection of the National Institute of Standards and Technology (NIST) Post-Quantum Cryptography (PQC) standardization algorithms, research on integrating PQC into security protocols such as TLS/SSL, IPSec, and DNSSEC has been actively pursued. However, PQC migration for Internet of Things (IoT) communication protocols remains largely unexplored. Embedded devices in IoT environments have limited computational power and memory, making it crucial to optimize PQC algorithms for efficient computation and minimal memory usage when deploying them on low-spec IoT devices. In this paper, we introduce KEM-MQTT, a lightweight and efficient Key Encapsulation Mechanism (KEM) for the Message Queuing Telemetry Transport (MQTT) protocol, widely used in IoT environments. Our approach applies the NIST KEM algorithm Crystals-Kyber (Kyber) while leveraging MQTT’s characteristics and sensor node constraints. To enhance efficiency, we address certificate verification issues and adopt KEMTLS to eliminate the need for Post-Quantum Digital Signatures Algorithm (PQC-DSA) in mutual authentication. As a result, KEM-MQTT retains its lightweight properties while maintaining the security guarantees of TLS 1.3. We identify inefficiencies in existing Kyber implementations on 8-bit AVR microcontrollers (MCUs), which are highly resource-constrained. To address this, we propose novel implementation techniques that optimize Kyber for AVR, focusing on high-speed execution, reduced memory consumption, and secure implementation, including Signed LookUp-Table (LUT) Reduction. Our optimized Kyber achieves performance gains of 81%,75%, and 85% in the KeyGen, Encaps, and DeCaps processes, respectively, compared to the reference implementation. With approximately 3 KB of stack usage, our Kyber implementation surpasses all state-of-the-art Elliptic Curve Diffie-Hellman (ECDH) implementations. Finally, in KEM-MQTT using Kyber-512, an 8-bit AVR device completes the handshake preparation process in 4.32 seconds, excluding the physical transmission and reception times.

Metadata
Available format(s)
PDF
Category
Implementation
Publication info
Published elsewhere. Minor revision. Asia-CCS 2025
Keywords
Post-Quantum CryptographyCrystals-KyberML-KEMMQTT8-bit AVRKEMTLS
Contact author(s)
darania @ kookmin ac kr
scseo @ kookmin ac kr
History
2025-03-29: revised
2025-03-27: received
See all versions
Short URL
https://ia.cr/2025/563
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/563,
      author = {YoungBeom Kim and Seog Chung Seo},
      title = {An Optimized Instantiation of Post-Quantum {MQTT} protocol on 8-bit {AVR} Sensor Nodes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/563},
      year = {2025},
      url = {https://eprint.iacr.org/2025/563}
}
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