### A Compact Digital Signature Scheme Based on the Module-LWR problem*

Hiroki Okada, Atsushi Takayasu, Kazuhide Fukushima, Shinsaku Kiyomoto, and Tsuyoshi Takagi

##### Abstract

We propose a lattice-based digital signature scheme MLWRSign by modifying Dilithium, which is one of the third-Round finalists of NIST’s call for post-quantum cryptographic standards. To the best of our knowledge, our scheme MLWRSign is the first signature scheme whose security is based on the (module) learning with rounding (LWR) problem. Due to the simplicity of the LWR, the secret key size is reduced by approximately 30% in our scheme compared to Dilithium, while achieving the same level of security. Moreover, we implemented MLWRSign and observed that the running time of MLWRSign is comparable to that of Dilithium.

Note: This paper is a revised version of [OTF+21]. We have corrected an error in Eq. (3), and slightly modified the Sign procedure of MLWRSign. See Appendix A for the details.

Available format(s)
Category
Public-key cryptography
Publication info
Published elsewhere. MINOR revision.IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E104.A(9), pp. 1219–1234
DOI
10.1587/transfun.2020DMP0012
Keywords
Lattice CryptographyDigital SignaturesLearning with Rounding
Contact author(s)
History
Short URL
https://ia.cr/2021/1699

CC BY

BibTeX

@misc{cryptoeprint:2021/1699,
author = {Hiroki Okada and Atsushi Takayasu and Kazuhide Fukushima and Shinsaku Kiyomoto and Tsuyoshi Takagi},
title = {A Compact Digital Signature Scheme Based on the Module-LWR problem*},
howpublished = {Cryptology ePrint Archive, Paper 2021/1699},
year = {2021},
doi = {10.1587/transfun.2020DMP0012},
note = {\url{https://eprint.iacr.org/2021/1699}},
url = {https://eprint.iacr.org/2021/1699}
}

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