Design and Cryptanalysis of ZUC: A Stream Cipher in Mobile Telephony (SpringerBriefs on Cyber Security Systems and Networks)

This book is a timely document of state-of-the art analytical techniques in the domain of stream cipher design and analysis with a specific cipher, named ZUC. It links new research to brief contextual literature review in the domain of complex LFSR-based stream ciphers. A snapshot of how stream ciphers are deployed in the mobile telephony architecture, one of the most well-known topics for more than five decades in the domain of computer and communication sciences, is presented in this book. The book provides an in-depth study on design and cryptanalysis of ZUC as well as relevant research results in this field with directions towards future analysis of this cipher. Foreword 7 Preface 9 Contents 13 About the Authors 15 Notations 16 1 Introduction and Preliminaries 18 1.1 Introduction 18 1.2 Symmetric Key Cryptosystem 19 1.3 Prerequisites 21 1.3.1 Finite Fields 21 1.3.2 Field Extension 23 1.3.3 LFSR-Based Stream Cipher 26 1.4 Nonlinear Combiner and Filter Generator Model 30 1.5 Cryptographic Properties of Boolean Function 31 1.6 Overview on 3GPP and Where ZUC Stands 37 1.6.1 ZUC 38 1.7 Confidentiality and Integrity Using Stream Cipher 39 References 41 2 Telephony Architecture 43 2.1 Outline of Security Protocols 43 2.2 The Architecture of the Different Generations 43 2.2.1 GSM/2G 44 2.2.2 UMTS/3G 47 2.2.3 LTE/4G Architecture 51 2.2.4 New Radio (NR)/5G 53 References 57 3 Design Specification of ZUC Stream Cipher 59 3.1 Structure of ZUC 59 3.1.1 Linear Feedback Shift Register of ZUC 60 3.1.2 Bit Reorganization Layer of ZUC 61 3.1.3 Nonlinear Function of ZUC (F) 62 3.2 Working Principle of ZUC 1.4 64 3.3 Differences Between ZUC 1.4 and ZUC 1.6 70 3.4 Confidentiality Algorithm Using ZUC 71 3.4.1 Initialization Phase 72 3.4.2 Keystream Generation Phase 73 3.4.3 Encryption/Decryption Phase 73 3.5 Integrity Algorithm 74 3.5.1 Initialization Phase 74 3.5.2 Keystream Generation Phase 75 3.5.3 Generation of MAC 75 3.6 Description of ZUC-256 76 3.6.1 Generation of MAC in ZUC-256 77 References 78 4 Cryptanalysis on ZUC 1.4 79 4.1 Analysis of ZUC 79 4.1.1 Analysis of the S-Box 79 4.1.2 Reversibility of ZUC 81 4.2 Differential Attack on ZUC 1.4 91 4.2.1 Difference in the First Byte of IV 93 4.2.2 Difference in the Second Byte of IV 100 4.3 Forgery Attack on EIA-128 100 4.3.1 Methodology of the Forgery Attack 101 References 103 5 Concluding Remarks 104 References 106 Appendix Test Vectors for ZUC 108 Index 111