In some applications for synchronous stream ciphers, the risk of loss of synchroniration cannot be eliminated completely. In these cases frequent rcsynchroniration or resynduonisation upon request may be necessary. In the paper it is shown that this can lead to significant deterioration of the cryptographic security. A powerful general attack on nonlinearly filtered linear (over Z,) systems is ...

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...

The nonlinear filter generator (NLFG) is a powerful building block commonly used in stream ciphers. In this paper, we present the direct sum decomposition of the NLFG output sequence that leads to a system of linear equations in the initial state of the NLFG and further to an efficient algebraic attack. The coefficients of the equation system rely only on the NLFG structure. The attack is opera...

detection and modification of the risk factors of stroke may be the most effective strategy for preventing its often irreversible consequences. a longitudinal prospective study was implemented to evaluate the effect of several risk factors on the course of cerebrovascular disease. the study groups were composed of 3s8 normal volunteers, and 308 patients with transient ischemic attacks. the two ...

The mere number of various apparently different statistical attacks on block ciphers has raised the question about their relationships which would allow to classify them and determine those that give essentially complementary information about the security of block ciphers. While mathematical links between some statistical attacks have been derived in the last couple of years, the important lin...

Our purpose is to describe a promising linear algebraic attack on the AAFG1 braid group cryptosystem proposed in [2] employing parameters suggested by the authors. Our method employs the well known Burau matrix representation of the braid group and techniques from computational linear algebra and provide evidence which shows that at least a certain class of keys are weak. We argue that if AAFG1...

In recent years, three main types of attacks have been developed against Feistel-based ciphers, such as DES[1]; these attacks are linear cryptanalysis[2], differential cryptanalysis[3], and the Davies and Murphy attack[4]. Using the discrete Fourier transform, we present here a quantitative criterion of security against the Davies and Murphy attack. Similar work has been done on linear and diff...

We investigate adversarial attacks for autoencoders. We propose a procedure that distorts the input image to mislead the autoencoder in reconstructing a completely different target image. We attack the internal latent representations, attempting to make the adversarial input produce an internal representation as similar as possible as the target’s. We find that autoencoders are much more robust...

We present a technique which uses multiple linear approximations in the linear cryptanalysis of a block cipher and allows for a reduction in the amount of data required for a successful attack. Although the method using many linear approximations was already suggested by B. Kaliski and M. Robshaw in 1994, this paper describes an revisited version utilizing a lot of approximations. In this paper...