Johannes Buchmann – författare

Cryptography is a key technology in electronic key systems. It is used to keep data secret, digitally sign documents, access control, and so forth. Users therefore should not only know how its techniques work, but they must also be able to estimate their efficiency and security. Based on courses taught by the author, this book explains the basic methods of modern cryptography. It is written for readers with only basic mathematical knowledge who are interested in modern cryptographic algorithms and their mathematical foundation. Several exercises are included following each chapter. This revised and extended edition includes new material on the AES encryption algorithm, the SHA-1 Hash algorithm, on secret sharing, as well as updates in the chapters on factoring and discrete logarithms.

Cryptography is a key technology in electronic security systems. Modern cryptograpic techniques have many uses, such as to digitally sign documents, for access control, to implement electronic money, and for copyright protection. Because of these important uses it is necessary that users be able to estimate the efficiency and security of cryptographic techniques. It is not sufficient for them to know only how the techniques work. This book is written for readers who want to learn about mod- ern cryptographic algorithms and their mathematical foundation but who do not have the necessary mathematical background. It is my goal to explain the basic techniques of modern cryptography, including the necessary mathematical results from linear algebra, algebra, number theory, and probability theory. I assume only basic mathematical knowledge. The book is based on courses in cryptography that I have been teaching at the Technical University, Darmstadt, since 1996. I thank all students who attended the courses and who read the manuscript carefully for their interest and support.In particular, I would like to thank Harald Baier, Gabi Barking, Manuel Breuning, Sa- fuat Hamdy, Birgit Henhapl, Michael Jacobson (who also corrected my English), Andreas Kottig, Markus Maurer, Andreas Meyer, Stefan v vi Preface Neis, Sachar Paulus, Thomas Pfahler, Marita Skrobic, Edlyn Thske, Patrick Theobald, and Ralf-Philipp Weinmann. I also thank the staff at Springer-Verlag, in particular Martin Peters, Agnes Herrmann, Claudia Kehl, Ina Lindemann, and Thrry Kornak, for their support in the preparation of this book.

This book constitutes the refereed proceedings of the 11th International Conference on the Theory and Application of Cryptographic Techniques in Africa, AFRICACRYPT 2019, held in Rabat, Morocco, in July 2019. The 22 papers presented in this book were carefully reviewed and selected from 53 submissions. The papers are organized in topical sections on protocols; post-quantum cryptography; zero-knowledge; lattice based cryptography; new schemes and analysis; block ciphers; side-channel attacks and countermeasures; signatures. AFRICACRYPT is a major scientific event that seeks to advance and promote the field of cryptology on the African continent. The conference has systematically drawn some excellent contributions to the field. The conference has always been organized in cooperation with the International Association for Cryptologic Research (IACR).

This book presents refereed proceedings of the First International Conference on Algebra, Codes and Cryptology, A2C 2019, held in Dakar, Senegal, in December 2019. The 14 full papers were carefully reviewed and selected from 35 submissions.

Homomorphic signature schemes are an important primitive for many applications and since their introduction numerous solutions have been presented. Thus, in this work we provide the first exhaustive, complete, and up-to-date survey about the state of the art of homomorphic signature schemes. First, the general framework where homomorphic signatures are defined is described and it is shown how the currently available types of homomorphic signatures can then be derived from such a framework. In addition, this work also presents a description of each of the schemes presented so far together with the properties it provides. Furthermore, three use cases, electronic voting, smart grids, and electronic health records, where homomorphic signature schemes can be employed are described. For each of these applications the requirements that a homomorphic signature scheme should fulfill are defined and the suitable schemes already available are listed. This also highlights the shortcomings of current solutions. Thus, this work concludes with several ideas for future research in the direction of homomorphic signature schemes.

This book presents the first comprehensive overview of various verifiable computing techniques, which allow the computation of a function on outsourced data to be delegated to a server. It provides a brief description of all the approaches and highlights the properties each solution achieves. Further, it analyzes the level of security provided, how efficient the verification process is, who can act as a verifier and check the correctness of the result, which function class the verifiable computing scheme supports, and whether privacy with respect to t he input and/or output data is provided. On the basis of this analysis the authors then compare the different approaches and outline possible directions for future work.The book is of interest to anyone wanting to understand the state of the art of this research field.

The book deals with algorithmic problems related to binary quadratic forms. It uniquely focuses on the algorithmic aspects of the theory. The book introduces the reader to important areas of number theory such as diophantine equations, reduction theory of quadratic forms, geometry of numbers and algebraic number theory. The book explains applications to cryptography and requires only basic mathematical knowledge. The author is a world leader in number theory.

This book contains 23 contributions presented at the "International Conference on Coding Theory, Cryptography and Related Areas (ICCC)", held in Guanajuato, Mexico, in April 1998.It comprises a series of research papers on various aspects of coding theory (geometric-algebraic, decoding, exponential sums, etc.) and cryptography (discrete logarithm problem, public key cryptosystems, primitives, etc.), as well as in other research areas, such as codes over finite rings and some aspects of function fields and algebraic geometry over finite fields.The book contains new results on the subject, never published in any other form. It will be useful to students, researchers, professionals, and tutors interested in this area of research.

This book constitutes the refereed proceedings of the Second International Workshop on Post-Quantum Cryptography, PQCrypto 2008, held in Cincinnati, OH, USA, in October 2008. The 15 revised full papers presented were carefully reviewed and selected from numerous submissions. Quantum computers are predicted to break existing public key cryptosystems within the next decade. Post-quantum cryptography is a new fast developing area, where public key schemes are studied that could resist these emerging attacks. The papers present four families of public key cryptosystems that have the potential to resist quantum computers: the code-based public key cryptosystems, the hash-based public key cryptosystems, the lattice-based public key cryptosystems and the multivariate public key cryptosystems.

Leading experts have joined forces for the first time to explain the state of the art in quantum computing, hash-based cryptography, code-based cryptography, lattice-based cryptography, and multivariate cryptography.

This book deals with algorithmic problems concerning binary quadratic forms 2 2 f(X,Y)= aX +bXY +cY with integer coe?cients a, b, c, the mathem- ical theories that permit the solution of these problems, and applications to cryptography. A considerable part of the theory is developed for forms with real coe?cients and it is shown that forms with integer coe?cients appear in a natural way. Much of the progress of number theory has been stimulated by the study of concrete computational problems. Deep theories were developed from the classic time of Euler and Gauss onwards to this day that made the solutions ofmanyof theseproblemspossible.Algorithmicsolutionsandtheirproperties became an object of study in their own right. Thisbookintertwinestheexpositionofoneveryclassicalstrandofnumber theory with the presentation and analysis of algorithms both classical and modern which solve its motivating problems. This algorithmic approach will lead the reader, we hope, not only to an understanding of theory and solution methods, but also to an appreciation of the e?ciency with which solutions can be reached. The computer age has led to a marked advancement of algorithmic - search. On the one hand, computers make it feasible to solve very hard pr- lems such as the solution of Pell equations with large coe?cients. On the other, the application of number theory in public-key cryptography increased the urgency for establishing the complexity of several computational pr- lems: many a computer system stays only secure as long as these problems remain intractable.

Leading experts have joined forces for the first time to explain the state of the art in quantum computing, hash-based cryptography, code-based cryptography, lattice-based cryptography, and multivariate cryptography.

This book constitutes the refereed proceedings of the 15th International Conference on Practice and Theory in Public Key Cryptography, PKC 2012, held in Darmstadt, Germany, in May 2012. The 41 papers presented were carefully reviewed and selected from 188 submissions. The book also contains one invited talk. The papers are organized in the following topical sections: homomorphic encryption and LWE, signature schemes, code-based and multivariate crypto, public key encryption: special properties, identity-based encryption, public-key encryption: constructions, secure two-party and multi-party computations, key exchange and secure sessions, public-key encryption: relationships, DL, DDH, and more number theory, and beyond ordinary signature schemes.

A thorough multidisciplinary analysis of various perspectives on internet privacy was published as the first volume of a study, revealing the results of the achatech project "Internet Privacy - A Culture of Privacy and Trust on the Internet." The second publication from this project presents integrated, interdisciplinary options for improving privacy on the Internet utilising a normative, value-oriented approach. The ways in which privacy promotes and preconditions fundamental societal values and how privacy violations endanger the flourishing of said values are exemplified. The conditions which must be fulfilled in order to achieve a culture of privacy and trust on the internet are illuminated. This volume presents options for policy-makers, educators, businesses and technology experts how to facilitate solutions for more privacy on the Internet and identifies further research requirements in this area.

Oftmals wird in der Manuellen Medizin oder den verschiedenen Schulen der Osteopathie versucht, eine Primärläsion (d.h. eine dem Störungsbild des Patienten zugrunde liegende Ur-Blockierung oder ein Trauma) zu identifizieren. Die Behandlung der Primärläsion würde dann die Symptome auflösen. Dieser Monokausalität setzten die Autoren einen vielfältigeren Ansatz entgegen: Da Patienten erst beim Entstehen von Schmerz den Arzt aufsuchen, sehen Manualmediziner fast ausschließlich Verkettungen. Fast regelhaft wird der Schmerz durch Trigger- und Tenderpunkte verursacht. Nach Meinung der Autoren kommt es darauf an herauszufinden, innerhalb welcher manualmedizinischer Syndrome diese Punkte entstanden sind und sie dann in den gefundenen Verkettungen zu behandeln. Neu ist die Formulierung manualmedizinischer Syndrome in Anlehnung an etablierte Klassifikationen. Klassische Therapieoptionen werden übersichtsweise dargestellt. Ausführlich wird dagegen auf die osteopathische Therapieplanung und die resultierenden Therapiemöglichkeiten eingegangen. Ein Buch aus der Praxis für die Praxis!

Dieses Kryptographiebuch ist geschrieben für Studierende der Mathematik, Informatik, Physik, Elektrotechnik oder andere Leser mit mathematischer Grundbildung und wurde in vielen Vorlesungen erfolgreich eingesetzt.

Dieses Buch beschreibt ausführlich die Techniken der manualmedizinisch-osteopathischen Untersuchung und Behandlung bei Säuglingen und Kindern im Kleinkind- und Schulalter.  Der Schwerpunkt liegt dabei auf der Berücksichtigung der kindlichen Besonderheiten, abweichend von den Techniken beim Erwachsenen. Alle Techniken werden mit brillanten Fotos visualisiert. Präzise und didaktisch klar strukturierte Texte beschreiben für jede Technik das „How-to-do“ und bieten Vorschläge zu deren rationellem Einsatz. Damit ist das Buch ideal für die systematische Einführung in die Praxis und als Nachschlagewerk im klinischen Alltag von bei Kindern manualmedizinisch tätigen Ärzten und Physiotherapeuten geeignet.