Cryptanalysis of 4-Pass HAVAL

HAVAL is a cryptographic hash function proposed by Zheng et al. Rompay et al and Wang et al found collisions of full 3-Pass HAVAL. In this paper, we study the security of 4-Pass HAVAL. We find collisions of full versions of 4-Pass HAVAL. The attack is similar to the two-block attack of MD5 proposed by Wang et al. The computational complexity of the attack is about 2^30-2^32 for the first block and 2^27-2^29 for the second block. We use this attack to find 256bit collisions of 4-Pass HAVAL in 3-4 hour on a common PC

On the possibility of constructing meaningful hash collisions for public keys

It is sometimes argued that finding meaningful hash collisions might prove difficult. We show that for several common public key systems it is easy to construct pairs of meaningful and secure public key data that either collide or share other characteristics with the hash collisions as quickly constructed by Wang et al. We present some simple results, investigate what we can and cannot (yet) achieve, and formulate some open problems of independent interest. We are not yet aware of truly interesting practical implications. Nevertheless, our results may be relevant for the practical assessment of the recent hash collision results. For instance, we show how to construct two different X.509 certificates that contain identical signatures. © Springer-Verlag Berlin Heidelberg 2005

an attack on hash function haval-128

Abstract In this paper, we give a fast attack against hash function——HAVAL-128