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Many online applications, especially in the financial industries, are running on blockchain technologies in a decentralized manner, without the use of an authoritative entity or a trusted third party. Such systems are only secured by cryptographic protocols and a consensus mechanism. As blockchain-based solutions will continue to revolutionize online applications in a growing digital market in the future, one needs to identify the principal opportunities and potential risks. Hence, it is unavoidable to learn the mathematical and cryptographic procedures behind blockchain technology in order to understand how such systems work and where the weak points are. The book provides an introduction to the mathematical and cryptographic concepts behind blockchain technologies and shows how they are applied in blockchain-based systems. This includes an introduction to the general blockchain technology approaches that are used to build the so-called immutable ledgers, which are based on cryptographic signature schemes. As future quantum computers will break some of the current cryptographic primitive approaches, the book considers their security and presents the current research results that estimate the impact on blockchain-based systems if some of the cryptographic primitive break. Based on the example of Bitcoin, it shows that weak cryptographic primitives pose a possible danger for the ledger, which can be overcome through the use of the so-called post-quantum cryptographic approaches which are introduced as well.

Cryptography is a vital technology that underpins the security of information in computer networks. This book presents a comprehensive introduction to the role that cryptography plays in providing information security for technologies such as the Internet, mobile phones, payment cards, and wireless local area networks. Focusing on the fundamental principles that ground modern cryptography as they arise in modern applications, it avoids both an over-reliance on transient technologies and overwhelming theoretical research. The first part of the book provides essential background, identifying the core security services provided by cryptography. The next part introduces the main cryptographic mechanisms that deliver these security services such as encryption, hash functions, and digital signatures, discussing why they work and how to deploy them, without delving into any significant mathematical detail. In the third part, the important practical aspects of key management are introduced, which is essential for making cryptography work in real systems. The last part considers the application of cryptography. A range of application case studies is presented, alongside a discussion of the wider societal issues arising from use of cryptography to support contemporary cyber security.

The subject of this book is the efficient solution of partial differential equations (PDEs) that arise when modelling incompressible fluid flow. The first part (Chapters 1 through 5) covers the Poisson equation and the Stokes equations. For each PDE, there is a chapter concerned with finite element discretization and a companion chapter concerned with efficient iterative solution of the algebraic equations obtained from discretization. Chapter 5 describes the basics of PDE-constrained optimization. The second part of the book (Chapters 6 to 11) is a more advanced introduction to the numerical analysis of incompressible flows. It starts with four chapters on the convection–diffusion equation and the steady Navier–Stokes equations, organized by equation with a chapter describing discretization coupled with a companion concerned with iterative solution algorithms. The book concludes with two chapters describing discretization and solution methods for models of unsteady flow and buoyancy-driven flow.

Today, Games User Research forms an integral component of the development of any kind of interactive entertainment. User research stands as the primary source of business intelligence in the incredibly competitive game industry. This book aims to provide the foundational, accessible, go-to resource for people interested in GUR. It is a community-driven effort—it is written by passionate professionals and researchers in the GUR community as a handbook and guide for everyone interested in user research and games. The book bridges the current gaps of knowledge in Game User Research, building the go-to volume for everyone working with games, with an emphasis on those new to the field.

This book is an introduction to elementary algebraic topology for students with an interest in computers and computer programming. Its aim is to illustrate how the basics of the subject can be implemented on a computer. The transition from basic theory to practical computation raises a range of non-trivial algorithmic issues and it is hoped that the treatment of these will also appeal to readers already familiar with basic theory who are interested in developing computational aspects. The book covers a subset of standard introductory material on fundamental groups, covering spaces, homology, cohomology and classifying spaces as well as some less standard material on crossed modules, homotopy 2- types and explicit resolutions for an eclectic selection of discrete groups. It attempts to cover these topics in a way that hints at potential applications of topology in areas of computer science and engineering outside the usual territory of pure mathematics, and also in a way that demonstrates how computers can be used to perform explicit calculations within the domain of pure algebraic topology itself. The initial chapters include examples from data mining, biology and digital image analysis, while the later chapters cover a range of computational examples on the cohomology of classifying spaces that are likely beyond the reach of a purely paper-and-pen approach to the subject. The applied examples in the initial chapters use only low-dimensional and mainly abelian topological tools. Our applications of higher dimensional and less abelian computational methods are currently confined to pure mathematical calculations. The approach taken to computational homotopy is very much based on J.H.C. Whitehead’s theory of combinatorial homotopy in which he introduced the fundamental notions of CW-space, simple homotopy equivalence and crossed module. The book should serve as a self-contained informal introduction to these topics and their computer implementation. It is written in a style that tries to lead as quickly as possible to a range of potentially useful machine computations.

This book is a technical, historical, and conceptual investigation into the three main methodological approaches to the computational sciences: mathematical, engineering, and experimental. Part I explores the background behind the formal understanding of computing, originating at the end of the nineteenth century, and it invesitagtes the formal origins and conceptual development of the notions of computation, algorithm, and program.Part II overviews the construction of physical devices to performautomated tasks and it considers associated technical and conceptual issues. It starts with the design and construction of the first generation of computingmachines, explores their evolution and progress in engineering (for both hardware and software), and investigates their theoretical and conceptual problems. Part III analyses the methods and principles of experimental sciences founded on computationalmethods. It studies the use ofmachines to performscientific tasks,with particular reference to computer models and simulations. Each part aims at defining a notion of computational validity according to the corresponding methodological approach.

The last 25 years have seen a small revolution in our approach to the understanding of new technology and information systems. It has become a founding assumption of computer-supported cooperative work and human–computer interaction that in the future, if not already, most computer applications will be socially embedded in the sense that they will become infrastructures (in some sense) for the development of the social practices which they are designed to support. Assuming that IT artifacts have to be understood in this sociotechnical way, traditional criteria for good design in computer science, such as performance, reliability, stability or usability, arguably need to be supplemented by methods and perspectives which illuminate the way in which technology and social practice are mutually elaborating. This book concerns the philosophy, conceptual apparatus, and methodological concerns which will inform the development of a systematic and long-term human-centered approach to the IT-product life cycle, addressing issues concerned with appropriation and infrastructuring. This entails an orientation to “practice-based computing.” The book contains a number of chapters which examine both the conceptual foundations of such an approach, and a number of empirical case studies that exemplify it.