CryptoDB

Paper: Quantum Collision Attacks on Reduced SHA-256 and SHA-512

Authors: Akinori Hosoyamada , NTT Corporation and Nagoya University Yu Sasaki , NTT Corporation Search ePrint Search Google Slides CRYPTO 2021 In this paper, we study dedicated quantum collision attacks on SHA-256 and SHA-512 for the first time. The attacks reach 38 and 39 steps, respectively, which significantly improve the classical attacks for 31 and 27 steps. Both attacks adopt the framework of the previous work that converts many semi-free-start collisions into a 2-block collision, and are faster than the generic attack in the cost metric of time-space tradeoff. We observe that the number of required semi-free-start collisions can be reduced in the quantum setting, which allows us to convert the previous classical 38 and 39 step semi-free-start collisions into a collision. The idea behind our attacks is simple and will also be applicable to other cryptographic hash functions.
BibTeX
@inproceedings{crypto-2021-31144,
title={Quantum Collision Attacks on Reduced SHA-256 and SHA-512},
publisher={Springer-Verlag},