Contents Preface v Acknowledgments ix Overview xi CHAPTER 1 Introduction 1 1.1 Background 1 1.1.1 Progress in Secure Communication 2 1.1.2 A New Technique for Secure Communication:Information Hiding 4 1.2 Introduction to Speech Coding 9 1.2.1 Basic Principles of Speech Coding 10 1.2.2 Speech Coding Standards 11 1.3 Related Work 14 1.4 Analysis of Available Information Hiding Methods 19 1.4.1 Least Significant Bit 19 1.4.2 Phase Hiding Method 20 1.4.3 Echo Hiding Method 20 1.4.4 Hiding Method Based on Statistics 21 1.4.5 Transform Domain Method 21 1.5 Organization of This Book 23 CHAPTER 2 The Information Hiding Model for Speech Secure Communication 27 2.1 Introduction and Motivation 27 2.2 Model of Information Hiding as a Communication Problem 29 2.3 Speech Information Hiding Model 31 2.3.1 Hiding Capacity 33 2.3.2 Security 33 2.3.3 Speech Quality 35 2.4 Experiments and Results Analysis 37 2.4.1 Hiding Capacity 37 2.4.2 Security 37 2.4.3 Speech Quality 38 2.5 Summary 4 CHAPTER 3 The ABS Speech Information Hiding Algorithm Based on Filter Similarity 41 3.1 Introduction and Motivation 41 3.1.1 Brief Introduction to the ABS Scheme 41 3.1.2 Analysis of the ABS Scheme 44 3.2 Filter Similarity 46 3.3 LPC Coefficient Substitution Based on Filter Similarity 50 3.3.1 LPC Substitution Algorithm 51 3.3.2 Multicodebook 52 3.4 Secret Speech Information Hiding and Extraction Algorithm 52 3.4.1 Speech Information Hiding Algorithm 54 3.4.2 Speech Information Extraction Algorithm 55 3.5 Experimental Results and Analysis 55 3.5.1 Selection of Test Parameters 56 3.5.2 Experimental Results 57 3.5.3 Calculation Complexity 58 3.5.4 Speech Quality 59 3.6 Summary 59 CHAPTER 4 The G.721-Based Speech Information Hiding Approach 65 4.1 Introduction to the G.721 Coding Standard 65 4.1.1 Differential Pulse Code Modulation 65 4.1.2 Adaptive Schemes 66 4.2 The Approach to Hide Secret Speech in G.721 71 4.2.1 Embedding Algorithm 71 4.2.2 Extraction Algorithm 76 4.3 Experimental Results and Analysis 77 4.3.1 Hiding Capacity 77 4.3.2 Speech Quality 78 4.4 Summary 80 CHAPTER 5 The G.728-Based Speech Information Hiding Approach 81 5.1 Code Excited Linear Prediction 81 5.1.1 The CELP Speech Production Model 81 5.1.2 Coding Principles 82 5.1.3 Encoder Operation 83 5.1.4 Perceptual Weighting 84 5.1.5 Vector Quantization 85 5.2 Introduction to the G.728 Coding Standard 85 5.3 The CELP-Based Scheme of Speech Information Hiding and Extraction 87 5.3.1 Embedding Scheme 87 5.3.2 Extraction Scheme 90 5.4 Approach to Hide Secret Speech in G.728 90 5.4.1 Embedding Algorithm 91 5.4.2 Extraction Algorithm 92 5.5 Experimental Results and Analysis 93 5.6 Summary 94 CHAPTER 6 The G.729-Based Speech Information Hiding Approach 97 6.1 Introduction to the G.729 Coding Standard 97 6.1.1 Algebraic Codebook Structure 97 6.1.2 Adaptive Codebook 98 6.l.3 G.729 Coding Scheme 102 6.2 The ACELP-Based Scheme of Speech Information Hiding and Extraction 104 6.2.1 Embedding Scheme 104 6.2.2 Extraction Scheme 108 6.3 Approach to Hide Secret Speech in G.729 108 6.3.1 Embedding Algorithm 108 6.3.2 Extraction Algorithm 110 6.4 Experimental Results and Analysis 110 6.5 Summary 111 CHAPTER 7 The GSM (RPE-LTP)-Based Speech Information Hiding Approach 113 7.1 Introduction to the GSM (RPE-LTP) Coding Standard 113 7.1.1 RPE-LTP Coding Scheme 114 7.l.2 GSM Coding Scheme 116 7.2 Approach to Hide Secret Speech in GSM (RPE-LTP) 120 7.2.1 Embedding Algorithm 120 7.2.2 Extraction Algorithm 121 7.3 Experimental Results and Analysis 122 7.4 Summary 126 CHAPTER 8 Covert Communication Based on the VolP System 127 8.1 Introduction to the VolP-Based Covert Communication System 127 8.1.1 Introduction to the VolP System 127 8.1.2 An Outline for VolP Steganography 128 8.l.3 Classifications of the Embedding Method 129 8.2 Modeling and Realization ofVolP-Based Covert Communication 130 8.3 Embedding Secret Speech into VolP G.729 Speech Flows 131 8.3.1 The CNT of G.729 Parameters 132 8.3.2 Embedding Approach Based on Matrix Coding 134 8.3.3 Embedding Procedure 136 8.3.4 Experimental Results and Analysis 138 8.4 Summary 142 CHAPTER 9 Design of Real-Time Speech Secure Communication over PSTN 143 9.1 Secure Communication Plan 143 9.1.1 Introduction 143 9.1.2 Requirements Analysis 144 9.2 Design and Realization of a Secure Communication System Based on PC 145 9.2.1 Framework for Design 145 9.2.2 Coding Scheme Selection 147 9.2.3 Multimedia Programming 147 9.2.4 System Realization 150 9.3 Speech Information Hiding Telephony (SIHT) Based on PSTN 152 9.3.1 Introduction 152 9.3.2 Description of the SIHT 153 9.3.3 Speech Information Hiding Scheme 55 9.3.4 SIHT Module 156 9.3.5 SIHT Operating Modes 160 9.3.6 Architecture of SIHT 161 9.4 Summary 163 References 165 Index 175