Title
Lightweight Post-quantum Key Encapsulation for 8-bit AVR Microcontrollers
Abstract
Recent progress in quantum computing has increased interest in the question of how well the existing proposals for post-quantum cryptosystems are suited to replace RSA and ECC. While some aspects of this question have already been researched in detail (e.g. the relative computational cost of pre- and post-quantum algorithms), very little is known about the RAM footprint of the proposals and what execution time they can reach when low memory consumption rather than speed is the main optimization goal. This question is particularly important in the context of the Internet of Things (IoT) since many IoT devices are extremely constrained and possess only a few kB of RAM. We aim to contribute to answering this question by exploring the software design space of the lattice-based key-encapsulation scheme ThreeBears on an 8-bit AVR microcontroller. More concretely, we provide new techniques for the optimization of the ring arithmetic of ThreeBears (which is, in essence, a 3120-bit modular multiplication) to achieve either high speed or low RAM footprint, and we analyze in detail the trade-offs between these two metrics. A low-memory implementation of BabyBear that is secure against Chosen Plaintext Attacks (CPA) needs just about 1.7 kB RAM, which is significantly below the RAM footprint of other lattice-based cryptosystems reported in the literature. Yet, the encapsulation time of this RAM-optimized BabyBear version is below 12.5 million cycles, which is less than the execution time of scalar multiplication on Curve25519. The decapsulation is more than four times faster and takes roughly 3.4 million cycles on an ATmega1284 microcontroller.
Year
DOI
Venue
2020
10.1007/978-3-030-68487-7_2
SMART CARD RESEARCH AND ADVANCED APPLICATIONS, CARDIS 2020
Keywords
DocType
Volume
Post-quantum cryptography, Key encapsulation mechanism, AVR architecture, Efficient implementation, Low RAM footprint
Conference
12609
ISSN
Citations 
PageRank 
0302-9743
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Hao Cheng104.73
Johann Großschädl200.34
Peter B. Rønne3129.33
Peter Y. A. Ryan400.34