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...

Linear cryptanalysis, along with differential cryptanalysis, is an important tool to evaluate the security of block ciphers. This work introduces a novel extension of linear cryptanalysis – zero-correlation linear cryptanalysis – a technique applicable to many block cipher constructions. It is based on linear approximations with a correlation value of exactly zero. For a permutation on n bits, ...

The conventional way of cryptanalysis is based on the cryptographic algorithms weak points examine. The attack model of conventional cryptanalysis covers mathematical description of the cryptographic algorithm used. This model is without any relation to the physical model implementation and without any relation to the real environment. Cryptographic algorithms currently used in the combination ...

Linear cryptanalysis, along with differential cryptanalysis, is an important tool to evaluate the security of block ciphers. This work introduces a novel extension of linear cryptanalysis: zero-correlation linear cryptanalysis, a technique applicable to many block cipher constructions. It is based on linear approximations with a correlation value of exactly zero. For a permutation on n bits, an...

Cryptanalysis of Bivium is presented with the help of a new Boolean system solver algorithm. This algorithm uses a Boolean equation model of Bivium for a known keystream. The Boolean solver uses implicant based computation of satisfying assignments and is distinct from well known CNF-satisfiability solvers or algebraic cryptanalysis methods. The solver is also inherently parallel and returns al...

This thesis presents some novel results on the cryptanalysis and design of stream ciphers. The first part of the thesis introduces various stream ciphers design and cryptanalysis techniques. The second part of the thesis gives the cryptanalysis of seven stream ciphers. The properties of addition are exploited in the cryptanalysis of two stream ciphers: the differential-linear cryptanalysis agai...

In [9], the notion of c-differentials was introduced as a potential expansion differential cryptanalysis against block ciphers utilizing substitution boxes. Drawing inspiration from technique higher order cryptanalysis, in this paper we propose c-derivatives and differentials investigate their properties. Additionally, consider how several classes functions, namely multiplicative inverse functi...

Linear cryptanalysis and diierential cryptanalysis are two recently introduced, powerful methodologies for attacking private-key block ciphers. In this paper, we examine the application of these two cryptanalysis techniques to a CAST-like encryption algorithm based on randomly generated s-boxes. It is shown that, when randomly generated substitution boxes (s-boxes) are used in a CAST-like algor...