In our constribution we explore a combination of local reduction with the method of syllogisms and the applications of generic
guessing strategies in the cryptanalysis of the block cipher GOST. Our experiments show that GOST with 64/128/256 bit key
requires at least 12/16/22 rounds to achieve full bit security against the method of syllogisms combined with the “maximum
In this paper we look at the security of two block ciphers which were both claimed in the published literature to be secure
against differential crypt-analysis (DC). However, a more careful examination shows that none of these ciphers is very secure
against... differential cryptanalysis, in particular if we consider attacks with sets of differentials. For both these ciphers
we report new perfectly periodic (iterative) aggregated differential attacks which propagate with quite high probabilities.
The first cipher we look at is GOST, a well-known Russian government encryption standard. The second cipher we look at is
PP-1, a very recent Polish block cipher. Both ciphers were designed to withstand linear and differential cryptanalysis. Unhappily,
both ciphers are shown to be much weaker than expected against advanced differential attacks. For GOST, we report better and
stronger sets of differentials than the best currently known attacks presented at SAC 2000  and propose the first attack
ever able to distinguish 16 rounds of GOST from random permutation. For PP-1 we show that in spite of the fact, that its S-box
has an optimal theoretical security level against differential cryptanalysis , , our differentials are strong enough
to allow to break all the known versions of the PP-1 cipher.
In this paper we introduce a novel block cipher based on the composition of abstract finite automata and Latin cubes. For information encryption and decryption the apparatus uses the same secret keys, which consist of key-automata based on composition of abstract finite automata such that the transition matrices of the component automata form Latin cubes. The aim of the paper is to show the essence of our algorithms not only for specialists working in compositions of abstract automata but also for all researchers interested in cryptosystems. Therefore, automata theoretical background of our results is not emphasized. The introduced cryptosystem is important also from a theoretical point of view, because it is the first fully functioning block cipher based on automata network.
. , Knudsen , L. R. , Leander , G. , Paar , C. , Poschmann , A. , Robshaw , M. J. B. , Seurin , Y. and Vikkelsoe , C. , PRESENT: An ultra-lightweight blockcipher , in: P. Paillier , I. Verbauwhede (eds.) CHES, LectureNotes in Computer