Paper 2020/517 Original: eprint.iacr.org/2020/517 ↗

Practical Product Proofs for Lattice Commitments

Thomas Attema
Vadim Lyubashevsky
Gregor Seiler
Abstract

We construct a practical lattice-based zero-knowledge argument for proving multiplicative relations between committed values. The underlying commitment scheme that we use is the currently most efficient one of Baum et al. (SCN 2018), and the size of our multiplicative proof ($9$KB) is only slightly larger than the $7$KB required for just proving knowledge of the committed values. We additionally expand on the work of Lyubashevsky and Seiler (Eurocrypt 2018) by showing that the above-mentioned result can also apply when working over rings $\mathbb{Z}_q[X]/(X^d+1)$ where $X^d+1$ splits into low-degree factors, which is a desirable property for many applications (e.g. range proofs, multiplications over $\mathbb{Z}_q$) that take advantage of packing multiple integers into the NTT coefficients of the committed polynomial.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2020-06-25: last updated
2020-05-05: published
Short URL
https://ia.cr/2020/517
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2020/517,
      author = {Thomas Attema and Vadim Lyubashevsky and Gregor Seiler},
      title = {Practical Product Proofs for Lattice Commitments},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/517},
      year = {2020},
      url = {https://eprint.iacr.org/2020/517}
}
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