Paper 2008/130
Analysis of Step-Reduced SHA-256
Florian Mendel, Norbert Pramstaller, Christian Rechberger, and Vincent Rijmen
Abstract
This is the first article analyzing the security of SHA-256 against fast collision search which considers the recent attacks by Wang et al. We show the limits of applying techniques known so far to SHA-256. Next we introduce a new type of perturbation vector which circumvents the identified limits. This new technique is then applied to the unmodified SHA-256. Exploiting the combination of Boolean functions and modular addition together with the newly developed technique allows us to derive collision-producing characteristics for step-reduced SHA-256, which was not possible before. Although our results do not threaten the security of SHA-256, we show that the low probability of a single local collision may give rise to a false sense of security.
Note: In Appendix C, this version gives the correct (shifted) characteristic. In Appendix D, this version corrects a 32-bit word in Table 10, and adapts some terms to a more standard nomenclature. Thanks to Somitra Kumar Sanadhyaand and Hongbo Yu for helping us to spot those errors.
Metadata
- Available format(s)
-
PDF
PS
- Publication info
- Published elsewhere. Fast Software Encryption (FSE) 2006. pp 126-143
- Contact author(s)
- christian rechberger @ iaik tugraz at
- History
- 2008-03-25: received
- Short URL
- https://ia.cr/2008/130
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2008/130,
author = {Florian Mendel and Norbert Pramstaller and Christian Rechberger and Vincent Rijmen},
title = {Analysis of Step-Reduced {SHA}-256},
howpublished = {Cryptology {ePrint} Archive, Paper 2008/130},
year = {2008},
url = {https://eprint.iacr.org/2008/130}
}
