Enhancing Differential-Linear Cryptanalysis
نویسندگان
چکیده
Differential cryptanalysis analyzes ciphers by studying the development of differences during encryption. Linear cryptanalysis is similar but is based on studying approximate linear relations. In 1994, Langford and Hellman showed that both kinds of analysis can be combined together by a technique called differential-linear cryptanalysis, in which the differential part creates a linear approximation with probability 1. They applied their technique to 8-round DES. In this paper we present an enhancement of differential-linear cryptanalysis in which the inherited linear probability is smaller than 1. We use this extension to describe a differential-linear distinguisher for a 7-round reducedversion of DES, and to present the best known key-recovery attack on a 9-round reduced-version of DES. We use our enhanced technique to attack COCONUT98 with time complexity 2 encryptions and 2 chosen plaintexts.
منابع مشابه
A new method for accelerating impossible differential cryptanalysis and its application on LBlock
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 ...
متن کاملImpossible Differential Cryptanalysis on Deoxys-BC-256
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...
متن کاملImpossible Differential Cryptanalysis of Reduced-Round Midori64 Block Cipher (Extended Version)
Impossible differential attack is a well-known mean to examine robustness of block ciphers. Using impossible differ- ential cryptanalysis, we analyze security of a family of lightweight block ciphers, named Midori, that are designed considering low energy consumption. Midori state size can be either 64 bits for Midori64 or 128 bits for Midori128; however, both vers...
متن کاملTowards a Unifying View of Block Cipher Cryptanalysis
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...
متن کاملResistance of Balanced s-Boxes to Linear and Differential Cryptanalysis
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...
متن کامل