Optimizing Crystals-Dilithium implementation in 16-bit MSP430 environment utilizing hardware multiplier

Abstract

Dilithium was selected as one of NIST standard Post Quantum Digital Signature algorithms and is undergoing standardization as a Module Lattice Digital Signature Algorithm (ML-DSA). However, until now research on optimization in embedded environments has primarily been conducted on ARM architectures, which are the basic benchmark targets. To prepare for future quantum secure Internet of Things environments, performance optimization on resource-constrained must be considered. Thus, in this paper, for the first time, we propose an optimized implementation of Dilithium in the 16-bit MSP430 environment, a low-resource device. We redesign the state-of-the-art optimization strategies for Dilithium to suit the MSP430 environment. By taking full advantage of MSP430’s hardware multiplier in the NTT-based polynomial multiplication, we achieve 73.0% and 80.1% of performance improvement for NTT and NTT⁻¹ compared to those in the reference implementation, which contributes about 5.5%–7.0%, 15.3%–17.5%, and 7.5%–10.0% of performance improvement compared to Dilithium’s public reference implementation for keypair generation, signing, and verification, respectively.