Paper 2026/459

Naor-Yung Transform for IND-CCA Probing Security with Lattice Instantiations

Katharina Boudgoust, LIRMM, Univ. Montpellier, CNRS
Laurent Imbert, LIRMM, Univ. Montpellier, CNRS
Loïc Masure, LIRMM, Univ. Montpellier, CNRS
Laz Panard, LIRMM, Univ. Montpellier, CNRS
Abstract

In this work, we propose novel security notions for encryption schemes that simulate an adversary in the black-box model equipped with additional side-channel power. More concretely, the adversary is allowed to probe values of the secret-key sensitive algorithms, i.e. key generation and decryption. We then prove a generalization of the well-known Naor-Yung (NY) transform, generically lifting IND-CPA secure encryption schemes to IND-CCA ones in this new probing context. Moreover, we instantiate the resulting framework from lattices, constructing Rutile, a masking-friendly IND-CPA encryption scheme inspired by Kyber, and then Topaz its IND-CCA secure extension. In our proposal, the masking-unfriendly parts of Kyber, namely the central binomial distributions and the FO-transform, are replaced by masking-friendly counterparts (sum of uniforms and the aforementioned NY-transform).

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
Probing SecurityLatticesNaor-Yung-TransformM-LWE
Contact author(s)
katharina boudgoust @ lirmm fr
laurent imbert @ lirmm fr
loic masure @ lirmm fr
laz panard @ lirmm fr
History
2026-03-07: approved
2026-03-05: received
See all versions
Short URL
https://ia.cr/2026/459
License
Creative Commons Attribution-NonCommercial
CC BY-NC

BibTeX

@misc{cryptoeprint:2026/459,
      author = {Katharina Boudgoust and Laurent Imbert and Loïc Masure and Laz Panard},
      title = {Naor-Yung Transform for {IND}-{CCA} Probing Security with Lattice Instantiations},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/459},
      year = {2026},
      url = {https://eprint.iacr.org/2026/459}
}
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