Learn More
Grøstl is a SHA-3 candidate proposal. Grøstl is an iterated hash function with a compression function built from two fixed, large, distinct permutations. The design of Grøstl is transparent and based on principles very different from those used in the SHA-family. The two permutations are constructed using the wide trail design strategy, which makes it(More)
Whirlpool is a hash function based on a block cipher that can be seen as a scaled up variant of the AES. The main difference is the (compared to AES) extremely conservative key schedule. In this work, we present a distinguishing attack on the full compression function of Whirlpool. We obtain this result by improving the rebound attack on reduced Whirlpool(More)
In this work, we propose the rebound attack, a new tool for the cryptanalysis of hash functions. The idea of the rebound attack is to use the available degrees of freedom in a collision attack to efficiently bypass the low probability parts of a differential trail. The rebound attack consists of an inbound phase with a match-in-the-middle part to exploit(More)
In this paper, we propose two new ways to mount attacks on the SHA-3 candidates Grøstl, and ECHO, and apply these attacks also to the AES. Our results improve upon and extend the rebound attack. Using the new techniques, we are able to extend the number of rounds in which available degrees of freedom can be used. As a result, we present the first attack on(More)
In this paper, we analyze the collision resistance of SHA-2 and provide the first results since the beginning of the NIST SHA-3 competition. We extend the previously best known semi-free-start collisions on SHA-256 from 24 to 32 (out of 64) steps and show a collision attack for 27 steps. All our attacks are practical and verified by colliding message pairs.(More)
In this work, we apply the rebound attack to the AES based SHA-3 candidate Lane. The hash function Lane uses a permutation based compression function, consisting of a linear message expansion and 6 parallel lanes. In the rebound attack on Lane, we apply several new techniques to construct a collision for the full compression function of Lane-256 and(More)
Grøstl is one of 14 second round candidates of the NIST SHA-3 competition. Cryptanalytic results on the wide-pipe compression function of Grøstl-256 have already been published. However, little is known about the hash function, arguably a much more interesting crypt-analytic setting. Also, Grøstl-512 has not been analyzed yet. In this paper , we show the(More)
We introduce the rebound attack as a variant of differential cryptanalysis on hash functions and apply it to the hash function Whirlpool, standardized by ISO/IEC. We give attacks on reduced variants of the 10-round Whirlpool hash function and compression function. Our results are collisions for 5.5 and near-collisions for 7.5 rounds on the hash function, as(More)