Impossible differential cryptanalysis, the extension of differential cryptanalysis, is one of the most efficient attacks against block ciphers. This cryptanalysis method has been applied to most of the block ciphers and has shown significant results. Using structures, key schedule considerations, early abort, and pre-computation are some common methods to reduce complexities of this attack. In ...

We introduce commutative diagram cryptanalysis, a framework for expressing certain kinds of attacks on product ciphers. We show that many familiar attacks, including linear cryptanalysis, differential cryptanalysis, differential-linear cryptanalysis, mod n attacks, truncated differential cryptanalysis, impossible differential cryptanalysis, higherorder differential cryptanalysis, and interpolat...

block ciphers have wide applications for hardware and software implementations. in this paper, a new block cipher algorithm with provable security is proposed. the whole structure of the algorithm is novel and has a good encryption and decryption performance. additionally, it has good security with few number of rounds. the structure of the proposed algorithm consists of 4-rounds feistel-like w...

1 Evaluation of security 1.1. Differential cryptanalysis In extending differential cryptanalysis, Aoki , Kobayashi, and Moriai [1] greatly reduced the computational amount needed [2]. They determined that differential cryptanalysis could not be applied to FEAL with more than 32 rounds. Biham et al. [3] proposed a new cyptanalysis of Skipjack [4] using impossible differentials. Although regular ...

In the SPN (Substitution-Permutation Network) structure, it is very important to design a diffusion layer to construct a secure block cipher against differential cryptanalysis and linear cryptanalysis. The purpose of this work is to prove that the SPN structure with a maximal diffusion layer provides a provable security against differential cryptanalysis and linear cryptanalysis in the sense th...

This paper describes an effort to attack S-DES using differential cryptanalysis and linear cryptanalysis. S-DES is a reduced version of the Data Encryption Standard (DES). It also includes a discussion on the subject of cryptology and a literature survey of useful papers regarding cryptography and cryptanalysis. This paper is meant as a tutorial on the fundamentals of differential cryptanalysis...

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...

Deoxys is a final-round candidate of the CAESAR competition. Deoxys is built upon an internal tweakable block cipher Deoxys-BC, where in addition to the plaintext and key, it takes an extra non-secret input called a tweak. This paper presents the first impossible differential cryptanalysis of Deoxys-BC-256 which is used in Deoxys as an internal tweakable block cipher. First, we find a 4.5-round...

In this letter, we study the marginal density of the XOR distribution table, and the linear approximation table entries of regular substitution boxes (s-boxes). Based on this, we show that the fraction of good s-boxes (with regard to immunity against linear and differential cryptanalysis) increases dramatically with the number of input variables. Introduction Differential cryptanalysis [1], and...