International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Shorter Lattice-Based Zero-Knowledge Proofs via One-Time Commitments

Vadim Lyubashevsky
Ngoc Khanh Nguyen
Gregor Seiler
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Abstract: There has been a lot of recent progress in constructing efficient zero-knowledge proofs for showing knowledge of an $\vec{\bm{s}}$ with small coefficients satisfying $\bm{A}\vec{\bm{s}}=\vec{\bm{t}}$. For typical parameters, the proof sizes have gone down from several megabytes to a bit under $50$KB (Esgin et al., Asiacrypt 2020). These are now within an order of magnitude of the sizes of lattice-based signatures, which themselves constitute proof systems which demonstrate knowledge of something weaker than the aforementioned equation. One can therefore see that this line of research is approaching optimality. In this paper, we modify a key component of these proofs, as well as apply several other tweaks, to achieve a further reduction of around $30\%$ in the proof output size. We also show that this savings propagates itself when these proofs are used in a general framework to construct more complex protocols.
Video from PKC 2021
  title={Shorter Lattice-Based Zero-Knowledge Proofs via One-Time Commitments},
  booktitle={Public-Key Cryptography - PKC 2021},
  author={Vadim Lyubashevsky and Ngoc Khanh Nguyen and Gregor Seiler},