Paper 2009/184 Original: eprint.iacr.org/2009/184 ↗
Cryptanalysis of Dynamic SHA(2)
Abstract
In this paper, we analyze the hash functions Dynamic SHA and Dynamic SHA2, which have been selected as first round candidates in the NIST hash function competition. These hash functions rely heavily on data-dependent rotations, similar to certain block ciphers, e.g., RC5. Our analysis suggests that in the case of hash functions, where the attacker has more control over the rotations, this approach is less favorable than in block ciphers. We present practical, or close to practical, collision attacks on both Dynamic SHA and Dynamic SHA2. Moreover, we present a preimage attack on Dynamic SHA that is faster than exhaustive search.
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2009-08-27: last updated
- 2009-05-02: published
- Short URL
- https://ia.cr/2009/184
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2009/184,
author = {Jean-Philippe Aumasson and Orr Dunkelman and Sebastiaan Indesteege and Bart Preneel},
title = {Cryptanalysis of Dynamic SHA(2)},
howpublished = {Cryptology {ePrint} Archive, Paper 2009/184},
year = {2009},
url = {https://eprint.iacr.org/2009/184}
}