Метод побудови S-блоків з властивістю кореляційної імунності координатних функцій

Розглядаються методи побудови кореляційно-імунних булевих функцій та еластичних функцій для синтеза криптографічних алгоритмів. Запропоновано евристичний алгоритм побудови збалансованої кореляційно-імунної функції, а також метод побудови S-блоків з властивістю кореляційної імунності першого порядку координатних функцій.Methods of construction of correlative-immune Boolean functions and resilient functions for synthesis of cryptographic algorithms are regarded. It is proposed heuristic algorithm of construction of balanced correlative-immune function, and also are proposed methods of construction of S-blocks with property of first-order correlative immunity of the coordinate functions

Balanced Boolean Functions with Nonlinearity > 2^{n-1} - 2^{(n-1)/2}

Recently, balanced 15-variable Boolean functions with nonlinearity 16266 were obtained by suitably modifying unbalanced Patterson-Wiedemann (PW) functions, which possess nonlinearity 2^{n-1}-2^{(n-1)/2}+20 = 16276. In this short paper, we present an idempotent interpreted as rotation symmetric Boolean function) with nonlinearity 16268 having 15 many zeroes in the Walsh spectrum, within the neighborhood of PW functions. Clearly this function can be transformed to balanced functions keeping the nonlinearity and autocorrelation distribution unchanged. The nonlinearity value of 16268 is currently the best known for balanced 15-variable Boolean functions. Furthermore, we have attained several balanced 13-variable Boolean functions with nonlinearity 4036, which improves the recent result of 4034

Оцінка загроз в розподілених мережах

Розглядаються питання захисту інформаційних ресурсів комунікаційної мережі зв’язку розподіленої обчислювальної мережі, наводяться характеристики й механізми реалізації загроз в розподілених мережах, наводиться їх класифікація і пропонується модель загроз.The questions of defense of informative resources of communication network of the distributed computer network are examined, description and mechanisms of realization of threats in the distributed networks is pointed, their classification is pointed and the model of threats is offered

Ongoing Research Areas in Symmetric Cryptography

This report is a deliverable for the ECRYPT European network of excellence in cryptology. It gives a brief summary of some of the research trends in symmetric cryptography at the time of writing. The following aspects of symmetric cryptography are investigated in this report: • the status of work with regards to different types of symmetric algorithms, including block ciphers, stream ciphers, hash functions and MAC algorithms (Section 1); • the recently proposed algebraic attacks on symmetric primitives (Section 2); • the design criteria for symmetric ciphers (Section 3); • the provable properties of symmetric primitives (Section 4); • the major industrial needs in the area of symmetric cryptography (Section 5)

D.STVL.9 - Ongoing Research Areas in Symmetric Cryptography

This report gives a brief summary of some of the research trends in symmetric cryptography at the time of writing (2008). The following aspects of symmetric cryptography are investigated in this report: • the status of work with regards to different types of symmetric algorithms, including block ciphers, stream ciphers, hash functions and MAC algorithms (Section 1); • the algebraic attacks on symmetric primitives (Section 2); • the design criteria for symmetric ciphers (Section 3); • the provable properties of symmetric primitives (Section 4); • the major industrial needs in the area of symmetric cryptography (Section 5)