## CryptoDB

### Paper: Improved Linear Approximations to ARX Ciphers and Attacks Against ChaCha

Authors: Murilo Coutinho Silva , CEPESC Tertuliano C. de Souza Neto , CEPESC Search ePrint Search Google EUROCRYPT 2021 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.
##### BibTeX
@inproceedings{eurocrypt-2021-30810,
title={Improved Linear Approximations to ARX Ciphers and Attacks Against ChaCha},
publisher={Springer-Verlag},
author={Murilo Coutinho Silva and Tertuliano C. de Souza Neto},
year=2021
}