Paper 2020/454

Optimized Lattice Basis Reduction In Dimension 2, and Fast Schnorr and EdDSA Signature Verification

Thomas Pornin

Abstract

We present an optimization of Lagrange's algorithm for lattice basis reduction in dimension 2. The optimized algorithm is proven to be correct and to always terminate with quadratic complexity; it uses more iterations on average than Lagrange's algorithm, but each iteration is much simpler to implement, and faster. The achieved speed is such that it makes application of the speed-up on ECDSA and EC Schnorr signatures described by Antipa et al worthwhile, even for very fast curves such as Ed25519. We applied this technique to signature verification in Curve9767, and reduced verification time by 30 to 33% on both small (ARM Cortex M0+ and M4) and large (Intel Coffee Lake with AVX2) architectures.

Metadata
Available format(s)
PDF
Category
Implementation
Publication info
Preprint. MINOR revision.
Keywords
lattice basis reductionelliptic curvecurve9767
Contact author(s)
thomas pornin @ nccgroup com
History
2020-04-20: received
Short URL
https://ia.cr/2020/454
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2020/454,
      author = {Thomas Pornin},
      title = {Optimized Lattice Basis Reduction In Dimension 2, and Fast Schnorr and {EdDSA} Signature Verification},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/454},
      year = {2020},
      url = {https://eprint.iacr.org/2020/454}
}
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