Electronic commerce is here to stay. No matter how big the dot-com crisis was or how far the e-entrepreneurs' shares fell in the market, the fact remains that there is still confidence in electronic trading. At least it would appear that investors are confident in e-companies again. However, not only trust of venture capitalists is of importance--consumers also have to have faith in on-line business. After all, without consumers there is no e-business. Interacting lawyers, technicians and economists are needed to create a trustworthy electronic commerce environment. To achieve this environment, thorough and inter-disciplinary research is required and that is exactly what this book is about. Researchers of the project Enabling Electronic Commerce from the Dutch universities of Tilburg and Eindhoven have chosen a number of e-topics to elaborate on trust from their point of view. This volume makes clear that the various disciplines can and will play a role in developing conditions for trust and thus contribute to a successful electronic market.

Information, Coding and Mathematics is a classic reference for both professional and academic researchers working in error-correction coding and decoding, Shannon theory, cryptography, digital communications, information security, and electronic engineering. The work represents a collection of contributions from leading experts in turbo coding, cryptography and sequences, Shannon theory and coding bounds, and decoding theory and applications. All of the contributors have individually and collectively dedicated their work as a tribute to the outstanding work of Robert J. McEliece. Information, Coding and Mathematics covers the latest advances in the widely used and rapidly developing field of information and communication technology.

The protection of sensitive information against unauthorized access or fraudulent changes has been of prime concern throughout the centuries. Modern communication techniques, using computers connected through networks, make all data even more vulnerable to these threats. In addition, new issues have surfaced that did not exist previously, e.g. adding a signature to an electronic document.Cryptology addresses the above issues - it is at the foundation of all information security. The techniques employed to this end have become increasingly mathematical in nature. Fundamentals of Cryptology serves as an introduction to modern cryptographic methods. After a brief survey of classical cryptosystems, it concentrates on three main areas. First, stream ciphers and block ciphers are discussed. These systems have extremely fast implementations, but sender and receiver must share a secret key. Second, the book presents public key cryptosystems, which make it possible to protect data without a prearranged key. Their security is based on intractable mathematical problems, such as the factorization of large numbers. The remaining chapters cover a variety of topics, including zero-knowledge proofs, secret sharing schemes and authentication codes. Two appendices explain all mathematical prerequisites in detail: one presents elementary number theory (Euclid's Algorithm, the Chinese Remainder Theorem, quadratic residues, inversion formulas, and continued fractions) and the other introduces finite fields and their algebraic structure.Fundamentals of Cryptology is an updated and improved version of An Introduction to Cryptology, originally published in 1988. Apart from a revision of the existing material, there are many new sections, and two new chapters on elliptic curves and authentication codes, respectively. In addition, the book is accompanied by a full text electronic version on CD-ROM as an interactive Mathematica manuscript.Fundamentals of Cryptology will be of interest to computer scientists, mathematicians, and researchers, students, and practitioners in the area of cryptography.

TO CRYPTOLOGY by Henk C. A. van Tilborg Eindhoven University of Technology THE NETHERLANDS l1li. . . KLUWER ACADEMIC PUBLISHERS Boston / Dordrecht " / Lancaster Dlstrlbuton for North America Kluwer Academic Publishers 101 Philip Drive Assinippi Park Norwell, Massachusetts 02061 USA Dlstrlbuton for the VK and lreland Kluwer Academic Publishers Falcon House, Queen Square Lancaster LAI IRN, UNITED KINGDOM Dlstrlbuton for aII other countrles Kluwer Academic Publishers Group Distribution Centre Post Office Box 322 3300 AH Dordrecht, THE NETHERLANDS Library of Congress Cataloglng-in-Publication Data Tilborg, Henk C. A. van, 1947- An introduction to cryptology. (The Kluwer international series in engineering and computer science) Bibliography: p. Includes index. 1. Cryptology. 2. Cyrptography-Data processing. 1. Title. II. Series. Z103. T54 1987 652'. 8 88-616 ISBN-I3: 978-1-4612-8955-5 e-ISBN-I3: 978-1-4613-1693-0 DOI: 10. 1007/978-1-4613-1693-0 Copyright (c) 1988 by Kluwer Academic Publishers Softcover reprint ofthe hardcover lst edition 1988 AlI rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher, Kluwer Academic Publishers, 101 Philip Drive, Assinippi Park, Norwell, Massachusetts 02061. 10 Marijke, who afler so many years stiU is an enigma 10 me CONTENTS page vii Contents ix Preface 1. INTRODUCfION 2. CLASSICAL SYSTEMS 7 2. 1. Caesar, simple substitutions, Vigenere 7 2. 2. The incidence of coincidences 11 2. 3. Vemam, Playfair, Transpositions, Hagelin, Enigma 14 19 3. SHIFf REGISTER SEQUENCES 3. 1.

The protection of sensitive information against unauthorized access or fraudulent changes has been of prime concern throughout the centuries. Modern communication techniques, using computers connected through networks, make all data even more vulnerable to these threats. In addition, new issues have surfaced that did not exist previously, e.g. adding a signature to an electronic document. Cryptology addresses the above issues - it is at the foundation of all information security. The techniques employed to this end have become increasingly mathematical in nature. Fundamentals of Cryptology serves as an introduction to modern cryptographic methods. After a brief survey of classical cryptosystems, it concentrates on three main areas. First, stream ciphers and block ciphers are discussed. These systems have extremely fast implementations, but sender and receiver must share a secret key. Second, the book presents public key cryptosystems, which make it possible to protect data without a prearranged key. Their security is based on intractable mathematical problems, such as the factorization of large numbers.The remaining chapters cover a variety of topics, including zero-knowledge proofs, secret sharing schemes and authentication codes. Two appendices explain all mathematical prerequisites in detail: one presents elementary number theory (Euclid's Algorithm, the Chinese Remainder Theorem, quadratic residues, inversion formulas, and continued fractions) and the other introduces finite fields and their algebraic structure. Fundamentals of Cryptology is an updated and improved version of An Introduction to Cryptology, originally published in 1988. Apart from a revision of the existing material, there are many new sections, and two new chapters on elliptic curves and authentication codes, respectively. Fundamentals of Cryptology will be of interest to computer scientists, mathematicians, and researchers, students, and practitioners in the area of cryptography.

TO CRYPTOLOGY by Henk C. A. van Tilborg Eindhoven University of Technology THE NETHERLANDS l1li. . . KLUWER ACADEMIC PUBLISHERS Boston / Dordrecht " / Lancaster Dlstrlbuton for North America Kluwer Academic Publishers 101 Philip Drive Assinippi Park Norwell, Massachusetts 02061 USA Dlstrlbuton for the VK and lreland Kluwer Academic Publishers Falcon House, Queen Square Lancaster LAI IRN, UNITED KINGDOM Dlstrlbuton for aII other countrles Kluwer Academic Publishers Group Distribution Centre Post Office Box 322 3300 AH Dordrecht, THE NETHERLANDS Library of Congress Cataloglng-in-Publication Data Tilborg, Henk C. A. van, 1947- An introduction to cryptology. (The Kluwer international series in engineering and computer science) Bibliography: p. Includes index. 1. Cryptology. 2. Cyrptography-Data processing. 1. Title. II. Series. Z103. T54 1987 652'. 8 88-616 ISBN-I3: 978-1-4612-8955-5 e-ISBN-I3: 978-1-4613-1693-0 DOI: 10. 1007/978-1-4613-1693-0 Copyright (c) 1988 by Kluwer Academic Publishers Softcover reprint ofthe hardcover lst edition 1988 AlI rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher, Kluwer Academic Publishers, 101 Philip Drive, Assinippi Park, Norwell, Massachusetts 02061. 10 Marijke, who afler so many years stiU is an enigma 10 me CONTENTS page vii Contents ix Preface 1. INTRODUCfION 2. CLASSICAL SYSTEMS 7 2. 1. Caesar, simple substitutions, Vigenere 7 2. 2. The incidence of coincidences 11 2. 3. Vemam, Playfair, Transpositions, Hagelin, Enigma 14 19 3. SHIFf REGISTER SEQUENCES 3. 1.

Information, Coding and Mathematics is a classic reference for both professional and academic researchers working in error-correction coding and decoding, Shannon theory, cryptography, digital communications, information security, and electronic engineering. The work represents a collection of contributions from leading experts in turbo coding, cryptography and sequences, Shannon theory and coding bounds, and decoding theory and applications. All of the contributors have individually and collectively dedicated their work as a tribute to the outstanding work of Robert J. McEliece. Information, Coding and Mathematics covers the latest advances in the widely used and rapidly developing field of information and communication technology.