Paper 2026/459 Original: eprint.iacr.org/2026/459 ↗
Naor-Yung Transform for IND-CCA Probing Security with Lattice Instantiations
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.
- History
- 2026-09-22: last updated
- 2026-03-05: published
- Short URL
- https://ia.cr/2026/459
- License
- https://creativecommons.org/licenses/by-nc/4.0/
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}
}