Abstract In this paper, we greatly increase the number of impossible differentials for SIMON and SIMECK by eliminating 1-bit constraint in input/output difference, which is precondition to ameliorate complexity attacks. We propose an algorithm can reduce searching find such trails efficiently since search space exponentially expands with multiple active bits. There another situation leading con...

Crypton is a 12-round block cipher proposed as an AES candidate and Crtpton v1.0 is the revised version. In this paper, we present two related-key impossible differential attacks to reduced-round Crypton and Crypton v1.0. By carefully choosing the relations of keys, constructing some 6round related-key differential trials and using some observations on the cipher, we first break 9-round Crypton...

This paper studies the search for the impossible differentials of E2. We apply the Shrinking technique, the miss-in-the-middle technique, and a new search algorithm to E2. As a result, no impossible differential is found for E2 with more than 5 rounds. We conclude that E2 is secure against cryptanalysis using impossible differentials derived by the currently known techniques.

Recently, a new kind of Generalized Unbalanced Feistel Network, denoted as GUFN-n, is proposed by Choy et al. at ACISP 2009. The advantages of this structure are that it allows parallel computations for encryption and it can provide provable security against traditional differential and linear cryptanalysis given that the round function is bijective. For this new structure, the designers also f...

This paper presents the first independent and systematic linear, differential and impossible-differential (ID) cryptanalyses of MIBS, a lightweight block cipher aimed at constrained devices such as RFID tags and sensor networks. Our contributions include linear attacks on up to 18-round MIBS, and the first ciphertext-only attacks on 13-round MIBS. Our differential analysis reaches 14 rounds, an...

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. We present the first automated tool f...

The impossible differential attack is one of the most fundamental tools cryptanalysis and has been successfully applied to a large variety block ciphers. In typical attack, foundation first step construct an differential. Nowadays, two kinds commonly used approaches in construction are matrix-based tool-aided automatic search methods. this paper, we proposed new method combining early-abort str...

Dear all, as announced in December the Grøstl hash function has been tweaked for the final round. The round3mods, updated specification, implementation and cryptanalysis are available at www.groestl.info. For the final round we have * significantly increased the size of the round constants to make the internal differential attack and its extensions impossible * and use different rotation consta...