In this document we present a new way to bound the probability of occurrence of an n-round differential in the context of differential cryptanalysis. Hence this new model allows us to claim proof of resistance against impossible differential cryptanalysis, as defined by Biham and al. in 1999. This work will be described through the example of CS-Cipher, to which, assuming some non-trivial hypot...

In this work we give some bounds which can be used to determine if a block cipher is secure against generalized linear cryptanalysis and partitioning cryptanalysis. For this purpose, we give a new de nition of imbalance which has some nice properties, and we show that an equivalent of Matsui's piling-up lemma holds for this de nition. The bounds are illustrated with examples. We prove that it s...

This paper aims to enhance the application of slide attack which is one of the most well-known cryptanalysis methods using selfsimilarity of a block cipher. The typical countermeasure against slide cryptanalysis is to use round-dependent constants. We present a new probabilistic technique and show how to overcome round-dependent constants in a slide attack against a block cipher based on the ge...

In this paper we present experiments in order to show how some pseudo random number generators can improve the effectiveness of a statistical cryptanalysis algorithm. We deduce mainly that a better generator enhance the accuracy of the cryptanalysis algorithm.

We present a cryptanalysis of a zero-knowledge identification protocol introduced by Naccache et al. at Eurocrypt ’95. Our cryptanalysis enables a polynomial-time attacker to pass the identification protocol with probability one, without knowing the private key.

to linear cryptanalysis. We also described how to sum up characteristics (which also hold in diierential cryptanalysis). The iteration of this characteristic to seven rounds have probability 1=2 ? 2 ?11. A similar characteristic exist with a reverse order of the bytes in each word. From the tables in 9] we can see that about 4 2 112 = 2 24 known plaintexts are required to attack Feal-8, with su...

In this paper, we discuss some of theory of provable security against differential and linear cryptanalysis. We also review the design principles of the block cipher KASUMI—especially its resistance against the basic forms of linear and differential cryptanalysis.