Camellia is a block cipher selected as a standard by ISO/IEC, which has been analyzed by a number of cryptanalysts. In this paper, we propose several 6-round impossible differential paths of Camellia with the FL/FL−1 layer in the middle of them. With the impossible differential and a well-organized precomputational table, impossible differential attacks on 10-round Camellia-192 and 11-round Cam...

Impossible differential cryptanalysis has shown to be a very powerful form of cryptanalysis against block ciphers. These attacks, even if extensively used, remain not fully understood because of their high technicality. Indeed, numerous are the applications where mistakes have been discovered or where the attacks lack optimality. This paper aims in a first step at formalizing and improving this...

Zero correlation linear cryptanalysis is a novel key recovery technique for block ciphers proposed in [5]. It is based on linear approximations with probability of exactly 1/2 (which corresponds to the zero correlation). Some block ciphers turn out to have multiple linear approximations with correlation zero for each key over a considerable number of rounds. Zero correlation linear cryptanalysi...

This paper shows a surprising similarity between the construction of, respectively, impossible differentials and square distinguishers. This observation is illustrated by comparing two attacks on IDEA (Biham & al., FSE’99 [2], Nakahara & al., 2001 [7]). Using this similarity, we also derive a 16-round square distinguisher on Skipjack, directly based on the impossible differential attack present...

The Advanced Encryption Standard (AES) is a 128-bit block cipher with a user key of 128, 192 or 256 bits, released by NIST in 2001 as the next-generation data encryption standard for use in the USA. It was adopted as an ISO international standard in 2005. Impossible differential cryptanalysis and the boomerang attack are powerful variants of differential cryptanalysis for analysing the security...

Camellia, a 128–bit block cipher which has been accepted by ISO/IEC as an international standard, is increasingly being used in many cryptographic applications. In this paper, using the redundancy in the key schedule and accelerating the filtration of wrong pairs, we present a new impossible differential attack to reduced–round Camellia. By this attack 12–round Camellia–128 without FL/FL−1 func...

TEA, XTEA and HIGHT are lightweight block ciphers with 64-bit block sizes and 128-bit keys. The round functions of the three ciphers are based on the simple operations XOR, modular addition and shift/rotation. TEA and XTEA are Feistel ciphers with 64 rounds designed by Needham and Wheeler, where XTEA is a successor of TEA, which was proposed by the same authors as an enhanced version of TEA. HI...

We propose a new method for evaluating the security of block ciphers against di erential cryptanalysis and propose new structures for block ciphers. To this end, we de ne the word-wise Markov (Feistel) cipher and random output-di erential (Feistel) cipher and clarify the relations among the di erential, the truncated di erential and the impossible di erential cryptanalyses of the random output-...

This paper deals with the security of MISTY structure with SPN round function. We study the lower bound of the number of active s-boxes for differential and linear characteristics of such block cipher construction. Previous result shows that the differential bound is consistent with the case of Feistel structure with SPN round function, yet the situation changes when considering the linear boun...