Paper 2025/106
NTRU+Sign: Compact NTRU-Based Signatures Using Bimodal Distributions
Abstract
We present a new lattice-based signature scheme, called ‘NTRU+Sign’, using the Fiat-Shamir with Aborts framework. The proposed scheme is designed based on a novel NTRU-based key structure that fits well with bimodal distributions, enabling efficiency improvements compared to its predecessor, BLISS. The novel NTRU-based key structure is characterized by: (1) effectively changing a modulus from 2q to q, which is different from the existing usage of 2q for bimodal distributions, and (2) drastically reducing the magnitude of a secret key, which directly leads to compactness of signature sizes. We provide two concrete parameter sets for NTRU+Sign, supporting 93-bit and 211-bit security levels. Using the technique from GALACTICS (that was suggested as the constant-time implementation of BLISS), our analysis shows that NTRU+Sign achieves a good balance between computational efficiency and signature compactness, with constant-time implementation. For instance, at the NIST-3 security level, NTRU+Sign produces signatures that are significantly smaller than Dilithium and HAETAE, while providing faster verification speeds. These advantages position NTRU+Sign as a competitive and practical solution for real-world deployments.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Preprint.
- Keywords
- Post-quantum cryptographyLattice-based signatures
- Contact author(s)
-
woojoo0121 @ korea ac kr
yoswuk @ korea ac kr
hongh @ korea ac kr
kak5175 @ korea ac kr
mkkim @ nsr re kr
lhc254 @ nsr re kr
jhpark @ smu ac kr - History
- 2025-01-24: last of 2 revisions
- 2025-01-23: received
- See all versions
- Short URL
- https://ia.cr/2025/106
- License
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CC BY
BibTeX
@misc{cryptoeprint:2025/106, author = {Joo Woo and Jonghyun Kim and Ga Hee Hong and Seungwoo Lee and Minkyu Kim and Hochang Lee and Jong Hwan Park}, title = {{NTRU}+Sign: Compact {NTRU}-Based Signatures Using Bimodal Distributions}, howpublished = {Cryptology {ePrint} Archive, Paper 2025/106}, year = {2025}, url = {https://eprint.iacr.org/2025/106} }