Paper 2021/224 Original: eprint.iacr.org/2021/224 ↗
Improved Linear Approximations to ARX Ciphers and Attacks Against ChaCha
Abstract
In this paper, we present a new technique which can be used to find better linear approximations in ARX ciphers. Using this technique, we present the first explicitly derived linear approximations for 3 and 4 rounds of ChaCha and, as a consequence, it enables us to improve the recent attacks against ChaCha. Additionally, we present new differentials for 3 and 3.5 rounds of ChaCha that, when combined with the proposed technique, lead to further improvement in the complexity of the Differential-Linear attacks against ChaCha.
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2021-09-22: last updated
- 2021-03-02: published
- Short URL
- https://ia.cr/2021/224
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2021/224,
author = {Murilo Coutinho and T. C. Souza Neto},
title = {Improved Linear Approximations to ARX Ciphers and Attacks Against ChaCha},
howpublished = {Cryptology {ePrint} Archive, Paper 2021/224},
year = {2021},
url = {https://eprint.iacr.org/2021/224}
}