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Stream Ciphers in Modern Real-time IT Systems

This book provides the most complete description, analysis, and comparative studies of modern standardized and most common stream symmetric encryption algorithms, as well as stream modes of symmetric block ciphers. Stream ciphers provide an encryption in almost real-time regardless of the volume and stream bit depth of converted data, which makes them the most popular in modern real-time IT systems. In particular, we analyze the criteria and performance indicators of algorithms, as well as the principles and methods of designing stream ciphers. Nonlinear-feedback shift registers, which are one of the main elements of stream ciphers, have been studied in detail. The book is especially useful for scientists, developers, and experts in the field of cryptology and electronic trust services, as well as for the training of graduate students, masters, and bachelors in the field of information security.

Software Requirement Patterns

Learn proven, real-world techniques for specifying software requirements with this practical reference. It details 30 requirement “patterns” offering realistic examples for situation-specific guidance for building effective software requirements. Each pattern explains what a requirement needs to convey, offers potential questions to ask, points out potential pitfalls, suggests extra requirements, and other advice. This book also provides guidance on how to write other kinds of information that belong in a requirements specification, such as assumptions, a glossary, and document history and references, and how to structure a requirements specification. A disturbing proportion of computer systems are judged to be inadequate; many are not even delivered; more are late or over budget. Studies consistently show one of the single biggest causes is poorly defined requirements: not properly defining what a system is for and what it’s supposed to do. Even a modest contribution to improving requirements offers the prospect of saving businesses part of a large sum of wasted investment. This guide emphasizes this important requirement need—determining what a software system needs to do before spending time on development. Expertly written, this book details solutions that have worked in the past, with guidance for modifying patterns to fit individual needs—giving developers the valuable advice they need for building effective software requirements

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