CRYPTOGRAPHY AND NETWORK SECURITY PRINCIPLES AND PRACTICE SEVENTH EDITION GLOBAL EDITION William Stallings Boston Columbus Indianapolis New York San Francisco Hoboken Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montréal Toronto Delhi Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo For Tricia: never dull, never boring, the smartest and bravest person I know Vice President and Editorial Director, ECS: Inventory Manager: Meredith Maresca Marcia J. Horton Senior Manufacturing Controller, Global Editions: Executive Editor: Tracy Johnson (Dunkelberger) Trudy Kimber Editorial Assistant: Kristy Alaura Media Production Manager, Global Editions: Acquisitions Editor, Global Editions: Abhijit Baroi Vikram Kumar Program Manager: Carole Snyder Product Marketing Manager: Bram Van Kempen Project Manager: Robert Engelhardt Marketing Assistant: Jon Bryant Project Editor, Global Editions: K. Neelakantan Cover Designer: Lumina Datamatics Media Team Lead: Steve Wright Cover Art: © goghy73 / Shutterstock R&P Manager: Rachel Youdelman Full-Service Project Management: R&P Senior Project Manager: William Opaluch Chandrakala Prakash, SPi Global Senior Operations Specialist: Maura Zaldivar-Garcia Composition: SPi Global Inventory Manager: Meredith Maresca Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on page 753. Pearson Education Limited Edinburgh Gate Harlow Essex CM20 2JE England and Associated Companies throughout the world Visit us on the World Wide Web at: www.com © Pearson Education Limited 2017 The right of William Stallings to be identified as the author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.
Authorized adaptation from the United States edition, entitled Cryptography and Network Security: Principles and Practice, 7th Edition, ISBN 978-0-13-444428-4, by William Stallings published by Pearson Education © 2017. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior written permission of the publisher or a license permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency Ltd, Saffron House, 6–10 Kirby Street, London EC1N 8TS. All trademarks used herein are the property of their respective owners.
The use of any trademark in this text does not vest in the author or publisher any trademark ownership rights in such trademarks, nor does the use of such trademarks imply any affiliation with or endorsement of this book by such owners. British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library 10 9 8 7 6 5 4 3 2 1 ISBN 10:1-292-15858-1 ISBN 13: 978-1-292-15858-7 Typeset by SPi Global Printed and bound in Malaysia. CONTENTS Notation 10 Preface 12 About the Author 18 PART ONE: BACKGROUND 19 Chapter 1 Computer and Network Security Concepts 19 1.1 Computer Security Concepts 21 1.2 The OSI Security Architecture 26 1.6 Fundamental Security Design Principles 34 1.7 Attack Surfaces and Attack Trees 37 1.8 A Model for Network Security 41 1.10 Key Terms, Review Questions, and Problems 44 Chapter 2 Introduction to Number Theory 46 2.1 Divisibility and the Division Algorithm 47 2.2 The Euclidean Algorithm 49 2.5 Fermat’s and Euler’s Theorems 64 2.6 Testing for Primality 68 2.7 The Chinese Remainder Theorem 71 2.9 Key Terms, Review Questions, and Problems 78 Appendix 2A The Meaning of Mod 82 PART TWO: SYMMETRIC CIPHERS 85 Chapter 3 Classical Encryption Techniques 85 3.1 Symmetric Cipher Model 86 3.6 Key Terms, Review Questions, and Problems 112 Chapter 4 Block Ciphers and the Data Encryption Standard 118 4.1 Traditional Block Cipher Structure 119 4.2 The Data Encryption Standard 129 4.4 The Strength of DES 134 3 4 CONTENTS 4.5 Block Cipher Design Principles 135 4.6 Key Terms, Review Questions, and Problems 137 Chapter 5 Finite Fields 141 5.4 Finite Fields of the Form GF(p) 147 5.6 Finite Fields of the Form GF(2n) 157 5.7 Key Terms, Review Questions, and Problems 169 Chapter 6 Advanced Encryption Standard 171 6.1 Finite Field Arithmetic 172 6.3 AES Transformation Functions 179 6.4 AES Key Expansion 190 6.5 An AES Example 193 6.7 Key Terms, Review Questions, and Problems 202 Appendix 6A Polynomials with Coefficients in GF(28) 203 Chapter 7 Block Cipher Operation 207 7.1 Multiple Encryption and Triple DES 208 7.3 Cipher Block Chaining Mode 216 7.4 Cipher Feedback Mode 218 7.5 Output Feedback Mode 220 7.7 XTS-AES Mode for Block-Oriented Storage Devices 224 7.8 Format-Preserving Encryption 231 7.9 Key Terms, Review Questions, and Problems 245 Chapter 8 Random Bit Generation and Stream Ciphers 250 8.1 Principles of Pseudorandom Number Generation 252 8.2 Pseudorandom Number Generators 258 8.3 Pseudorandom Number Generation Using a Block Cipher 261 8.6 True Random Number Generators 271 8.7 Key Terms, Review Questions, and Problems 280 PART THREE: ASYMMETRIC CIPHERS 283 Chapter 9 Public-Key Cryptography and RSA 283 9.1 Principles of Public-Key Cryptosystems 285 9.2 The RSA Algorithm 294 9.3 Key Terms, Review Questions, and Problems 308 CONTENTS 5 Chapter 10 Other Public-Key Cryptosystems 313 10.1 Diffie-Hellman Key Exchange 314 10.2 Elgamal Cryptographic System 318 10.3 Elliptic Curve Arithmetic 321 10.4 Elliptic Curve Cryptography 330 10.5 Pseudorandom Number Generation Based on an Asymmetric Cipher 334 10.6 Key Terms, Review Questions, and Problems 336 PART FOUR: CRYPTOGRAPHIC DATA INTEGRITY ALGORITHMS 339 Chapter 11 Cryptographic Hash Functions 339 11.1 Applications of Cryptographic Hash Functions 341 11.2 Two Simple Hash Functions 346 11.3 Requirements and Security 348 11.4 Hash Functions Based on Cipher Block Chaining 354 11.5 Secure Hash Algorithm (SHA) 355 11.7 Key Terms, Review Questions, and Problems 377 Chapter 12 Message Authentication Codes 381 12.1 Message Authentication Requirements 382 12.2 Message Authentication Functions 383 12.3 Requirements for Message Authentication Codes 391 12.4 Security of MACs 393 12.5 MACs Based on Hash Functions: HMAC 394 12.6 MACs Based on Block Ciphers: DAA and CMAC 399 12.7 Authenticated Encryption: CCM and GCM 402 12.9 Pseudorandom Number Generation Using Hash Functions and MACs 413 12.10 Key Terms, Review Questions, and Problems 416 Chapter 13 Digital Signatures 419 13.2 Elgamal Digital Signature Scheme 424 13.3 Schnorr Digital Signature Scheme 425 13.4 NIST Digital Signature Algorithm 426 13.5 Elliptic Curve Digital Signature Algorithm 430 13.6 RSA-PSS Digital Signature Algorithm 433 13.7 Key Terms, Review Questions, and Problems 438 PART FIVE: MUTUAL TRUST 441 Chapter 14 Key Management and Distribution 441 14.1 Symmetric Key Distribution Using Symmetric Encryption 442 14.2 Symmetric Key Distribution Using Asymmetric Encryption 451 14.3 Distribution of Public Keys 454 14.5 Public-Key Infrastructure 467 14.6 Key Terms, Review Questions, and Problems 469 Chapter 15 User Authentication 473 15.1 Remote User-Authentication Principles 474 15.2 Remote User-Authentication Using Symmetric Encryption 478 15.4 Remote User-Authentication Using Asymmetric Encryption 500 15.5 Federated Identity Management 502 15.6 Personal Identity Verification 508 15.7 Key Terms, Review Questions, and Problems 515 PART SIX: NETWORK AND INTERNET SECURITY 519 Chapter 16 Network Access Control and Cloud Security 519 16.1 Network Access Control 520 16.2 Extensible Authentication Protocol 523 16.1X Port-Based Network Access Control 527 16.5 Cloud Security Risks and Countermeasures 535 16.6 Data Protection in the Cloud 537 16.7 Cloud Security as a Service 541 16.8 Addressing Cloud Computing Security Concerns 544 16.9 Key Terms, Review Questions, and Problems 545 Chapter 17 Transport-Level Security 546 17.1 Web Security Considerations 547 17.2 Transport Layer Security 549 17.5 Key Terms, Review Questions, and Problems 579 Chapter 18 Wireless Network Security 581 18.2 Mobile Device Security 585 18.11 Wireless LAN Overview 589 18.11i Wireless LAN Security 595 18.5 Key Terms, Review Questions, and Problems 610 Chapter 19 Electronic Mail Security 612 19.1 Internet Mail Architecture 613 19.3 Email Threats and Comprehensive Email Security 625 19.5 Pretty Good Privacy 638 19.7 DNS-Based Authentication of Named Entities 643 19.8 Sender Policy Framework 645 19.9 DomainKeys Identified Mail 648 CONTENTS 7 19.10 Domain-Based Message Authentication, Reporting, and Conformance 654 19.11 Key Terms, Review Questions, and Problems 659 Chapter 20 IP Security 661 20.1 IP Security Overview 662 20.2 IP Security Policy 668 20.3 Encapsulating Security Payload 673 20.4 Combining Security Associations 681 20.5 Internet Key Exchange 684 20.7 Key Terms, Review Questions, and Problems 694 APPENDICES 696 Appendix A Projects for Teaching Cryptography and Network Security 696 A.1 Sage Computer Algebra Projects 697 A.3 Block Cipher Projects 699 A.7 Practical Security Assessments 700 A.11 Reading/Report Assignments 702 A.12 Discussion Topics 702 Appendix B Sage Examples 703 B.1 Linear Algebra and Matrix Functionality 704 B.2 Chapter 2: Number Theory 705 B.3 Chapter 3: Classical Encryption 710 B.4 Chapter 4: Block Ciphers and the Data Encryption Standard 713 B.5 Chapter 5: Basic Concepts in Number Theory and Finite Fields 717 B.6 Chapter 6: Advanced Encryption Standard 724 B.7 Chapter 8: Pseudorandom Number Generation and Stream Ciphers 729 B.8 Chapter 9: Public-Key Cryptography and RSA 731 B.9 Chapter 10: Other Public-Key Cryptosystems 734 B.10 Chapter 11: Cryptographic Hash Functions 739 B.11 Chapter 13: Digital Signatures 741 References 744 Credits 753 Index 754 8 CONTENTS ONLINE CHAPTERS AND APPENDICES1 PART SEVEN: SYSTEM SECURITY Chapter 21 Malicious Software 21.1 Types of Malicious Software (Malware) 21.2 Advanced Persistent Threat 21.3 Propagation—Infected Content—Viruses 21.4 Propagation—Vulnerability Exploit—Worms 21.5 Propagation—Social Engineering—Spam E-mail, Trojans 21.6 Payload—System Corruption 21.7 Payload—Attack Agent—Zombie, Bots 21.8 Payload—Information Theft—Keyloggers, Phishing, Spyware 21.9 Payload—Stealthing—Backdoors, Rootkits 21.11 Distributed Denial of Service Attacks 21.13 Key Terms, Review Questions, and Problems Chapter 22 Intruders 22.5 Key Terms, Review Questions, and Problems Chapter 23 Firewalls 23.1 The Need for Firewalls 23.2 Firewall Characteristics and Access Policy 23.3 Types of Firewalls 23.5 Firewall Location and Configurations 23.7 Key Terms, Review Questions, and Problems PART EIGHT: LEGAL AND ETHICAL ISSUES Chapter 24 Legal and Ethical Aspects 24.1 Cybercrime and Computer Crime 24.7 Key Terms, Review Questions, and Problems 24.A Information Privacy 1 Online chapters, appendices, and other documents are at the Companion Website, available via the access card at the front of this book. CONTENTS 9 Appendix C Sage Exercises Appendix D Standards and Standard-Setting Organizations Appendix E Basic Concepts from Linear Algebra Appendix F Measures of Secrecy and Security Appendix G Simplified DES Appendix H Evaluation Criteria for AES Appendix I Simplified AES Appendix J The Knapsack Algorithm Appendix K Proof of the Digital Signature Algorithm Appendix L TCP/IP and OSI Appendix M Java Cryptographic APIs Appendix N MD5 Hash Function Appendix O Data Compression Using ZIP Appendix P PGP Appendix Q The International Reference Alphabet Appendix R Proof of the RSA Algorithm Appendix S Data Encryption Standard Appendix T Kerberos Encryption Techniques Appendix U Mathematical Basis of the Birthday Attack Appendix V Evaluation Criteria for SHA-3 Appendix W The Complexity of Algorithms Appendix X Radix-64 Conversion Appendix Y The Base Rate Fallacy Glossary NOTATION Symbol Expression Meaning D, K D(K, Y) Symmetric decryption of ciphertext Y using secret key K D, PRa D(PRa, Y) Asymmetric decryption of ciphertext Y using A’s private key PRa D, PUa D(PUa, Y) Asymmetric decryption of ciphertext Y using A’s public key PUa E, K E(K, X) Symmetric encryption of plaintext X using secret key K E, PRa E(PRa, X) Asymmetric encryption of plaintext X using A’s private key PRa E, PUa E(PUa, X) Asymmetric encryption of plaintext X using A’s public key PUa K Secret key PRa Private key of user A PUa Public key of user A MAC, K MAC(K, X) Message authentication code of message X using secret key K The finite field of order p, where p is prime.The field is defined as GF(p) the set Zp together with the arithmetic operations modulo p.
GF(2n) The finite field of order 2n Zn Set of nonnegative integers less than n Greatest common divisor; the largest positive integer that gcd gcd(i, j) divides both i and j with no remainder on division. mod a mod m Remainder after division of a by m mod, K a K b (mod m) a mod m = b mod m mod, [ a [ b (mod m) a mod m ≠ b mod m dlog dlog a,p(b) Discrete logarithm of the number b for the base a (mod p) The number of positive integers less than n and relatively w f(n) prime to n. This is Euler’s totient function.