## CryptoDB

### Paper: Weaknesses of the FORK-256 compression function

Authors: Krystian Matusiewicz Scott Contini Josef Pieprzyk URL: http://eprint.iacr.org/2006/317 Search ePrint Search Google This report presents analysis of the compression function of a recently proposed hash function, FORK-256. We exhibit some unexpected differentials existing for the step transformation and show their possible uses in collision-finding attacks on different variants of FORK-256. As a simple application of those observations we present a method of finding chosen IV collisions for a variant of FORK-256 reduced to two branches : either 1 and 2 or 3 and 4. Moreover, we present how those differentials can be used in the full FORK-256 to easily find messages with hashes differing by only a relatively small number of bits. We argue that this method allows for finding collisions in the full function with complexity not exceeding $2^{126.6}$ hash evaluations, better than birthday attack and additionally requiring only a small amount of memory.
##### BibTeX
@misc{eprint-2006-21808,
title={Weaknesses of the FORK-256 compression function},
booktitle={IACR Eprint archive},
keywords={secret-key cryptography / hash functions, cryptanalysis, FORK-256},
url={http://eprint.iacr.org/2006/317},
note={ kmatus@ics.mq.edu.au 13481 received 14 Sep 2006, last revised 29 Nov 2006},
author={Krystian Matusiewicz and Scott Contini and Josef Pieprzyk},
year=2006
}