Computer Security (2^nd Ed.) Art and Science

The Comprehensive Guide to Computer Security, Extensively Revised with Newer Technologies, Methods, Ideas, and Examples

In this updated guide, University of California at Davis Computer Security Laboratory co-director Matt Bishop offers clear, rigorous, and thorough coverage of modern computer security. Reflecting dramatic growth in the quantity, complexity, and consequences of security incidents, Computer Security, Second Edition, links core principles with technologies, methodologies, and ideas that have emerged since the first edition?s publication.

Writing for advanced undergraduates, graduate students, and IT professionals, Bishop covers foundational issues, policies, cryptography, systems design, assurance, and much more. He thoroughly addresses malware, vulnerability analysis, auditing, intrusion detection, and best-practice responses to attacks. In addition to new examples throughout, Bishop presents entirely new chapters on availability policy models and attack analysis.

• Understand computer security goals, problems, and challenges, and the deep links between theory and practice
• Learn how computer scientists seek to prove whether systems are secure
• Define security policies for confidentiality, integrity, availability, and more
• Analyze policies to reflect core questions of trust, and use them to constrain operations and change
• Implement cryptography as one component of a wider computer and network security strategy
• Use system-oriented techniques to establish effective security mechanisms, defining who can act and what they can do
• Set appropriate security goals for a system or product, and ascertain how well it meets them
• Recognize program flaws and malicious logic, and detect attackers seeking to exploit them

This is both a comprehensive text, explaining the most fundamental and pervasive aspects of the field, and a detailed reference. It will help you align security concepts with realistic policies, successfully implement your policies, and thoughtfully manage the trade-offs that inevitably arise.

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Preface xxix

Acknowledgments xlv

About the Author xlix

Part I: Introduction 1

Chapter 1: An Overview of Computer Security 3

1.1 The Basic Components 3

1.2 Threats 6

1.3 Policy and Mechanism 9

1.4 Assumptions and Trust 11

1.5 Assurance 12

1.6 Operational Issues 16

1.7 Human Issues 20

1.8 Tying It All Together 22

1.9 Summary 24

1.10 Research Issues 24

1.11 Further Reading 25

1.12 Exercises 25

Part II: Foundations 29

Chapter 2: Access Control Matrix 31

2.1 Protection State 31

2.2 Access Control Matrix Model 32

2.3 Protection State Transitions 37

2.4 Copying, Owning, and the Attenuation of Privilege 42

2.5 Summary 44

2.6 Research Issues 44

2.7 Further Reading 44

2.8 Exercises 45

Chapter 3: Foundational Results 49

3.1 The General Question 49

3.2 Basic Results 51

3.3 The Take-Grant Protection Model 56

3.4 Closing the Gap: The Schematic Protection Model 68

3.5 Expressive Power and the Models 81

3.6 Comparing Security Properties of Models 94

3.7 Summary 101

3.8 Research Issues 102

3.9 Further Reading 102

3.10 Exercises 103

Part III: Policy 107

Chapter 4: Security Policies 109

4.1 The Nature of Security Policies 109

4.2 Types of Security Policies 113

4.3 The Role of Trust 115

4.4 Types of Access Control 117

4.5 Policy Languages 118

4.6 Example: Academic Computer Security Policy 126

4.7 Security and Precision 131

4.8 Summary 136

4.9 Research Issues 136

4.10 Further Reading 137

4.11 Exercises 138

Chapter 5: Confidentiality Policies 141

5.1 Goals of Confidentiality Policies 141

5.2 The Bell-LaPadula Model 142

5.3 Tranquility 161

5.4 The Controversy over the Bell-LaPadula Model 164

5.5 Summary 169

5.6 Research Issues 169

5.7 Further Reading 170

5.8 Exercises 171

Chapter 6: Integrity Policies 173

6.1 Goals 173

6.2 The Biba Model 175

6.3 Lipner’s Integrity Matrix Model 178

6.4 Clark-Wilson Integrity Model 183

6.5 Trust Models 189

6.6 Summary 196

6.7 Research Issues 196

6.8 Further Reading 197

6.9 Exercises 198

Chapter 7: Availability Policies 201

7.1 Goals of Availability Policies 201

7.2 Deadlock 202

7.3 Denial of Service Models 203

7.4 Example: Availability and Network Flooding 215

7.5 Summary 222

7.6 Research Issues 222

7.7 Further Reading 223

7.8 Exercises 224

Chapter 8: Hybrid Policies 227

8.1 Chinese Wall Model 227

8.2 Clinical Information Systems Security Policy 236

8.3 Originator Controlled Access Control 239

8.4 Role-Based Access Control 244

8.5 Break-the-Glass Policies 249

8.6 Summary 250

8.7 Research Issues 250

8.8 Further Reading 251

8.9 Exercises 252

Chapter 9: Noninterference and Policy Composition 255

9.1 The Problem 255

9.2 Deterministic Noninterference 259

9.3 Nondeducibility 271

9.4 Generalized Noninterference 274

9.5 Restrictiveness 277

9.6 Side Channels and Deducibility 280

9.7 Summary 282

9.8 Research Issues 283

9.9 Further Reading 283

9.10 Exercises 285

Part IV: Implementation I: Cryptography 287

Chapter 10: Basic Cryptography 289

10.1 Cryptography 289

10.2 Symmetric Cryptosystems 291

10.3 Public Key Cryptography 306

10.4 Cryptographic Checksums 315

10.5 Digital Signatures 318

10.6 Summary 323

10.7 Research Issues 324

10.8 Further Reading 325

10.9 Exercises 326

Chapter 11: Key Management 331

11.1 Session and Interchange Keys 332

11.2 Key Exchange 332

11.3 Key Generation 341

11.4 Cryptographic Key Infrastructures 343

11.5 Storing and Revoking Keys 353

11.6 Summary 359

11.7 Research Issues 360

11.8 Further Reading 361

11.9 Exercises 362

Chapter 12: Cipher Techniques 367

12.1 Problems 367

12.2 Stream and Block Ciphers 370

12.3 Authenticated Encryption 377

12.4 Networks and Cryptography 381

12.5 Example Protocols 384

12.6 Summary 410

12.7 Research Issues 411

12.8 Further Reading 411

12.9 Exercises 413

Chapter 13: Authentication 415

13.1 Authentication Basics 415

13.2 Passwords 416

13.3 Password Selection 418

13.4 Attacking Passwords 426

13.5 Password Aging 434

13.6 Challenge-Response 438

13.7 Biometrics 441

13.8 Location 445

13.9 Multifactor Authentication 446

13.10 Summary 448

13.11 Research Issues 449

13.12 Further Reading 450

13.13 Exercises 451

Part V: Implementation II: Systems 453

Chapter 14: Design Principles 455

14.1 Underlying Ideas 455

14.2 Principles of Secure Design 457

14.3 Summary 466

14.4 Research Issues 466

14.5 Further Reading 467

14.6 Exercises 468

Chapter 15: Representing Identity 471

15.1 What Is Identity? 471

15.2 Files and Objects 472

15.3 Users 473

15.4 Groups and Roles 475

15.5 Naming and Certificates 476

15.6 Identity on the Web 484

15.7 Anonymity on the Web 490

15.8 Summary 501

15.9 Research Issues 502

15.10 Further Reading 503

15.11 Exercises 504

Chapter 16: Access Control Mechanisms 507

16.1 Access Control Lists 507

16.2 Capabilities 518

16.3 Locks and Keys 526

16.4 Ring-Based Access Control 531

16.5 Propagated Access Control Lists 533

16.6 Summary 535

16.7 Research Issues 535

16.8 Further Reading 536

16.9 Exercises 536

Chapter 17: Information Flow 539

17.1 Basics and Background 539

17.2 Nonlattice Information Flow Policies 542

17.3 Static Mechanisms 548

17.4 Dynamic Mechanisms 562

17.5 Integrity Mechanisms 566

17.6 Example Information Flow Controls 567

17.7 Summary 574

17.8 Research Issues 574

17.9 Further Reading 575

17.10 Exercises 576

Chapter 18: Confinement Problem 579

18.1 The Confinement Problem 579

18.2 Isolation 582

18.3 Covert Channels 594

18.4 Summary 619

18.5 Research Issues 620

18.6 Further Reading 620

18.7 Exercises 622

Part VI: Assurance 625

Contributed by Elisabeth Sullivan and Michelle Ruppel

Chapter 19: Introduction to Assurance 627

19.1 Assurance and Trust 627

19.2 Building Secure and Trusted Systems 634

19.3 Summary 645

19.4 Research Issues 645

19.5 Further Reading 646

19.6 Exercises 647

Chapter 20: Building Systems with Assurance 649

20.1 Assurance in Requirements Definition and Analysis 649

20.2 Assurance during System and Software Design 662

20.3 Assurance in Implementation and Integration 685

20.4 Assurance during Operation and Maintenance 695

20.5 Summary 696

20.6 Research Issues 696

20.7 Further Reading 697

20.8 Exercises 698

Chapter 21: Formal Methods 699

21.1 Formal Verification Techniques 699

21.2 Formal Specification 702

21.3 Early Formal Verification Techniques 705

21.4 Current Verification Systems 713

21.5 Functional Programming Languages 721

21.6 Formally Verified Products 722

21.7 Summary 723

21.8 Research Issues 724

21.9 Further Reading 725

21.10 Exercises 725

Chapter 22: Evaluating Systems 727

22.1 Goals of Formal Evaluation 727

22.2 TCSEC: 1983-1999 730

22.3 International Efforts and the ITSEC: 1991-2001 737

22.4 Commercial International Security Requirements: 1991 742

22.5 Other Commercial Efforts: Early 1990s 744

22.6 The Federal Criteria: 1992 744

22.7 FIPS 140: 1994-Present 746

22.8 The Common Criteria: 1998-Present 749

22.9 SSE-CMM: 1997-Present 765

22.10 Summary 768

22.11 Research Issues 769

22.12 Further Reading 769

22.13 Exercises 770

Part VII: Special Topics 773

Chapter 23: Malware 775

23.1 Introduction 775

23.2 Trojan Horses 776

23.3 Computer Viruses 780

23.4 Computer Worms 790

23.5 Bots and Botnets 793

23.6 Other Malware 796

23.7 Combinations 803

23.8 Theory of Computer Viruses 803

23.9 Defenses 808

23.10 Summary 820

23.11 Research Issues 820

23.12 Further Reading 821

23.13 Exercises 822

Chapter 24: Vulnerability Analysis 825

24.1 Introduction 825

24.2 Penetration Studies 827

24.3 Vulnerability Classification 845

24.4 Frameworks 849

24.5 Standards 864

24.6 Gupta and Gligor’s Theory of Penetration Analysis 868

24.7 Summary 873

24.8 Research Issues 874

24.9 Further Reading 875

24.10 Exercises 876

Chapter 25: Auditing 879

25.1 Definition 879

25.2 Anatomy of an Auditing System 880

25.3 Designing an Auditing System 884

25.4 A Posteriori Design 893

25.5 Auditing Mechanisms 897

25.6 Examples: Auditing File Systems 900

25.7 Summary 910

25.8 Research Issues 911

25.9 Further Reading 912

25.10 Exercises 913

Chapter 26: Intrusion Detection 917

26.1 Principles 917

26.2 Basic Intrusion Detection 918

26.3 Models 920

26.4 Architecture 942

26.5 Organization of Intrusion Detection Systems 948

26.6 Summary 954

26.7 Research Issues 954

26.8 Further Reading 955

26.9 Exercises 956

Chapter 27: Attacks and Responses 959

27.1 Attacks 959

27.2 Representing Attacks 960

27.3 Intrusion Response 971

27.4 Digital Forensics 987

27.5 Summary 996

27.6 Research Issues 997

27.7 Further Reading 998

27.8 Exercises 999

Part VIII: Practicum 1003

Chapter 28: Network Security 1005

28.1 Introduction 1005

28.2 Policy Development 1006

28.3 Network Organization 1011

28.4 Availability 1026

28.5 Anticipating Attacks 1027

28.6 Summary 1028

28.7 Research Issues 1028

28.8 Further Reading 1029

28.9 Exercises 1030

Chapter 29: System Security 1035

29.1 Introduction 1035

29.2 Policy 1036

29.3 Networks 1042

29.4 Users 1048

29.5 Authentication 1053

29.6 Processes 1055

29.7 Files 1061

29.8 Retrospective 1066

29.9 Summary 1068

29.10 Research Issues 1068

29.11 Further Reading 1069

29.12 Exercises 1070

Chapter 30: User Security 1073

30.1 Policy 1073

30.2 Access 1074

30.3 Files and Devices 1080

30.4 Processes 1087

30.5 Electronic Communications 1092

30.6 Summary 1094

30.7 Research Issues 1095

30.8 Further Reading 1095

30.9 Exercises 1096

Chapter 31: Program Security 1099

31.1 Problem 1099

31.2 Requirements and Policy 1100

31.3 Design 1104

31.4 Refinement and Implementation 1111

31.5 Common Security-Related Programming Problems 1117

31.6 Testing, Maintenance, and Operation 1141

31.7 Distribution 1146

31.8 Summary 1147

31.9 Research Issues 1147

31.10 Further Reading 1148

31.11 Exercises 1148

Part IX: Appendices 1151

Appendix A: Lattices 1153

A.1 Basics 1153

A.2 Lattices 1154

A.3 Exercises 1155

Appendix B: The Extended Euclidean Algorithm 1157

B.1 The Euclidean Algorithm 1157

B.2 The Extended Euclidean Algorithm 1158

B.3 Solving ax mod n = 1 1160

B.4 Solving ax mod n = b 1161

B.5 Exercises 1161

Appendix C: Entropy and Uncertainty 1163

C.1 Conditional and Joint Probability 1163

C.2 Entropy and Uncertainty 1165

C.3 Joint and Conditional Entropy 1166

C.4 Exercises 1169

Appendix D: Virtual Machines 1171

D.1 Virtual Machine Structure 1171

D.2 Virtual Machine Monitor 1171

D.3 Exercises 1176

Appendix E: Symbolic Logic 1179

E.1 Propositional Logic 1179

E.2 Predicate Logic 1184

E.3 Temporal Logic Systems 1186

E.4 Exercises 1188

Appendix F: The Encryption Standards 1191

F.1 Data Encryption Standard 1191

F.2 Advanced Encryption Standard 1196

F.3 Exercises 1205

Appendix G: Example Academic Security Policy 1207

G.1 Acceptable Use Policy 1207

G.2 University of California Electronic Communications Policy 1212

G.3 User Advisories 1234

G.4 Electronic Communications—Allowable Use 1241

Appendix H: Programming Rules 1247

H.1 Implementation Rules 1247

H.2 Management Rules 1249

References 1251

Index 1341

Matt Bishop is a professor in the Department of Computer Science at the University of California at Davis. His main research interest is the analysis of vulnerabilities in computer systems, including modeling them, building tools to detect vulnerabilities, and ameliorating or eliminating them. He works in the areas of network security, including the study of denial of service attacks and defenses, policy modeling, software assurance testing, resilience, and formal modeling of access control. He was co-chair of the Joint Task Force that developed the Cybersecurity Curricula 2017: Curriculum Guidelines for Post-Secondary Degree Programs in Cybersecurity, released in December 2017. He earned his Ph.D. in computer science from Purdue University in 1984.

• Understand computer security goals, problems, and challenges, and the deep links between theory and practice
• Learn how computer scientists seek to prove whether systems are secure
• Define security policies for confidentiality, integrity, availability, and more
• Analyze policies to reflect core questions of trust, and use them to constrain operations and change
• Implement cryptography as one component of a wider computer and network security strategy
• Use system-oriented techniques to establish effective security mechanisms, defining who can act and what they can do
• Set appropriate security goals for a system or product, and ascertain how well it meets them
• Recognize program flaws and malicious logic, and detect attackers seeking to exploit them