A Compact Digital Signature Scheme Based on the Module-LWR Problem
Hiroki Okada, Atsushi Takayasu, Kazuhide Fukushima, Shinsaku Kiyomoto, Tsuyoshi Takagi · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences · 2021
We propose a new lattice-based digital signature scheme MLWRSign by modifying Dilithium, which is one of the second-round candidates 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 our scheme is comparable to that of Dilithium.