@inproceedings{ab4c272f5af2486ca64f014d5a37dbd9,
title = "Efficient Multiplication of Somewhat Small Integers Using Number-Theoretic Transforms",
abstract = "Conventional wisdom purports that FFT-based integer multiplication methods (such as the Sch{\"o}nhage–Strassen algorithm) begin to compete with Karatsuba and Toom–Cook only for integers of several tens of thousands of bits. In this work, we challenge this belief, leveraging recent advances in the implementation of number-theoretic transforms (NTT) stimulated by their use in post-quantum cryptography. We report on implementations of NTT-based integer arithmetic on two Arm Cortex-M CPUs on opposite ends of the performance spectrum: Cortex-M3 and Cortex-M55. Our results indicate that NTT-based multiplication is capable of outperforming the big-number arithmetic implementations of popular embedded cryptography libraries for integers as small as 2048 bits. To provide a realistic case study, we benchmark implementations of the RSA encryption and decryption operations. Our cycle counts on Cortex-M55 are about 10 × lower than on Cortex-M3.",
keywords = "Arm processors, FFT-based multiplication, NTT, RSA",
author = "Hanno Becker and Vincent Hwang and Kannwischer, {Matthias J.} and Lorenz Panny and Yang, {Bo Yin}",
note = "Publisher Copyright: {\textcopyright} 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.; 17th International Workshop on Security, IWSEC 2022 ; Conference date: 31-08-2022 Through 02-09-2022",
year = "2022",
doi = "10.1007/978-3-031-15255-9_1",
language = "English",
isbn = "9783031152542",
series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",
publisher = "Springer Science and Business Media Deutschland GmbH",
pages = "3--23",
editor = "Chen-Mou Cheng and Mitsuaki Akiyama",
booktitle = "Advances in Information and Computer Security - 17th International Workshop on Security, IWSEC 2022, Proceedings",
}