Deterministic Chaos in Digital Cryptography

This thesis studies the application of deterministic chaos to digital cryptography. Cryptographic systems such as pseudo-random generators (PRNG), block ciphers and hash functions are regarded as a dynamic system (X, j), where X is a state space (Le. message space) and f : X -+ X is an iterated function. In both chaos theory and cryptography, the object of study is a dynamic system that performs an iterative nonlinear transformation of information in an apparently unpredictable but deterministic manner. In terms of chaos theory, the sensitivity to the initial conditions together with the mixing property ensures cryptographic confusion (statistical independence) and diffusion (uniform propagation of plaintext and key randomness into cihertext). This synergetic relationship between the properties of chaotic and cryptographic systems is considered at both the theoretical and practical levels: The theoretical background upon which this relationship is based, includes discussions on chaos, ergodicity, complexity, randomness, unpredictability and entropy. Two approaches to the finite-state implementation of chaotic systems (Le. pseudo-chaos) are considered: (i) floating-point approximation of continuous-state chaos; (ii) binary pseudo-chaos. An overview is given of chaotic systems underpinning cryptographic algorithms along with their strengths and weaknesses. Though all conventional cryposystems are considered binary pseudo-chaos, neither chaos, nor pseudo-chaos are sufficient to guarantee cryptographic strength and security. A dynamic system is said to have an analytical solution Xn = (xo) if any trajectory point Xn can be computed directly from the initial conditions Xo, without performing n iterations. A chaotic system with an analytical solution may have a unpredictable multi-valued map Xn+l = f(xn). Their floating-point approximation is studied in the context of pseudo-random generators. A cryptographic software system E-Larm ™ implementing a multistream pseudo-chaotic generator is described. Several pseudo-chaotic systems including the logistic map, sine map, tangent- and logarithm feedback maps, sawteeth and tent maps are evaluated by means of floating point computations. Two types of partitioning are used to extract pseudo-random from the floating-point state variable: (i) combining the last significant bits of the floating-point number (for nonlinear maps); and (ii) threshold partitioning (for piecewise linear maps). Multi-round iterations are produced to decrease the bit dependence and increase non-linearity. Relationships between pseudo-chaotic systems are introduced to avoid short cycles (each system influences periodically the states of other systems used in the encryption session). An evaluation of cryptographic properties of E-Larm is given using graphical plots such as state distributions, phase-space portraits, spectral density Fourier transform, approximated entropy (APEN), cycle length histogram, as well as a variety of statistical tests from the National Institute of Standards and Technology (NIST) suite. Though E-Larm passes all tests recommended by NIST, an approach based on the floating-point approximation of chaos is inefficient in terms of the quality/performance ratio (compared with existing PRNG algorithms). Also no solution is known to control short cycles. In conclusion, the role of chaos theory in cryptography is identified; disadvantages of floating-point pseudo-chaos are emphasized although binary pseudo-chaos is considered useful for cryptographic applications.Durand Technology Limite

Proton Beam Emittance Growth in Run5 and Run6

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Formation of knowledge for agent technologies information security

It describes the content of the methodological basis of agent technologies. The problems of intelligent information agents in information security monitoring system. Obtained formalization of a system for the expansion of the methodological basis of agent technologies in information securityОписано содержание методологического базиса агентных технологий. Сформулированы задачи интеллектуальных информационных агентов в системе мониторинга информационной безопасности. Выделена система формализаций для расширения методологического базиса агентных технологий при обеспечении информационной безопасност

Creating a profile competence in information security in the research study

It formulated the main goal of the research practices in the magistracy in «Information Security». Defined profile professional competence. Submitted content requirements for knowledge and skills of students upon successful completion of practiceСформулирована основная цель научно-исследовательской практики в магистратуре по направлению «Информационная безопасность». Определены профильные профессиональные компетенции. Представлено содержание требований к знаниям и умениям студента после успешного завершения практик

BNL-built LHC magnet error impact analysis and compensation

Superconducting magnets built at the Brookhaven National Laboratory will be installed in both the Insertion Region IP2 and IP8, and the RF region of the Large Hadron Collider (LHC). In particular, field quality of these IR dipoles will become important during LHC heavy- ion operation when the beta * at IP2 is reduced to 0.5 meters. This paper studies the impact of the magnetic errors in BNL-built magnets on LHC performance at injection and collision, both for proton and heavy-ion operation. Methods and schemes for error compensation are considered including optimization of magnet orientation and compensation using local IR correctors. (2 refs)

The application of the SXF lattice description and the UAL software environment to the analysis of the LHC

A software environment for accelerator modeling has been developed which includes the UAL (Unified Accelerator Library), a collection of accelerator physics libraries with a Perl interface for scripting, and the SXF (Standard eX-change Format), a format for accelerator description which extends the MAD sequence by including deviations from design values. SXF interfaces have been written for several programs, including MAD9 and MAD8 via the doom database, Cosy, TevLat and UAL itself, which includes Teapot++. After an overview of the software we describe the application of the tools to the analysis of the LHC lattice stability, in the presence of alignment and coupling errors, and to the correction of the first turn and closed orbit in the machine. (7 refs)

Beam Based Measurements of Field Multipoles in the RHIC Low Beta Insertions and Extrapolation of the Method to the LHC

The multipolar content of the dipoles and quadrupoles is known to limit the stability of the beam dynamics in super-conducting machines like RHIC and even more in LHC. The low-beta quadrupoles are thus equipped with correcting coils up to the dodecapole order. The correction is planned to rely on magnetic measurements. We show that a relatively simple method allows an accurate measurement of the multipolar field aberrations using the beam. The principle is to displace the beam in the non-linear fields by local closed orbit bumps and to measure the variation of sensitive beam observable. The resolution and robustness of the method are found appropriate. Experimentation at RHIC showed clearly the presence of normal and skew sextupolar field components in addition to a skew quadrupolar component in the interaction regions. Higher-order components up to decapole order appear as well