About the Editors xiii
List of Contributors xv
Preface xix
Part I Preliminaries 1
1 Foundations of Physical-Layer Security for 6G 3
Matthieu Bloch
1.1 Coding Mechanisms 4
1.1.1 Channel Coding 5
1.1.2 Soft Covering 6
1.1.3 Source Coding with Side Information 7
1.1.4 Privacy Amplification 8
1.2 Coding for Physical-Layer Security 8
1.2.1 Secure Communication 9
1.2.2 Secret-Key Generation 11
1.3 Engineering and Learning Channels 12
References 13
2 Coding Theory Advances in Physical-Layer Secrecy 19
Laura Luzzi
2.1 Introduction 19
2.2 Wiretap Coding Schemes Based on Coset Coding 20
2.2.1 LDPC Codes for Binary Erasure Wiretap Channels 21
2.2.2 Polar Codes for Binary Input Symmetric Channels 26
2.2.3 Lattice Codes for Gaussian and Fading Wiretap Channels 29
2.3 Wiretap Coding Schemes Based on Invertible Extractors 31
2.3.1 Secrecy Capacity-Achieving Codes for the Gaussian Channel 35
2.4 Finite-Length Results 35
References 38
Part II Physical-Layer Security in Emerging Scenarios 43
3 Beamforming Design for Secure IRS-Assisted Multiuser MISO Systems 45
Dongfang Xu, Derrick Wing Kwan Ng, and Robert Schober
3.1 Introduction 45
3.2 System Model 47
3.3 Resource Allocation Optimization Problem 49
3.3.1 Performance Metrics of Secure Communication 49
3.3.2 Problem Formulation 50
3.4 Solution of the Optimization Problem 50
3.4.1 Problem Reformulation 50
3.4.2 Successive Convex Approximation 52
3.4.3 Complex Circle Optimization 53
3.4.3.1 Tangent Space 54
3.4.3.2 Riemannian Gradient 54
3.5 Experimental Results 58
3.5.1 Average SSR Versus BS Power Budget 59
3.5.2 Average SSR Versus Number of Legitimate Users 60
3.6 Conclusion 61
3.7 Future Extension 61
References 63
4 Physical-Layer Security for Optical Wireless Communications 67
Shenjie Huang, Mohammad Dehghani Soltani, and Majid Safari
4.1 Introduction 67
4.2 PLS for SISO VLC 68
4.2.1 PLS Performance Metrics 68
4.2.2 SISO VLC Secrecy Analysis 69
4.3 PLS for MISO VLC 74
4.3.1 MISO VLC Secrecy Analysis 75
4.3.2 Secrecy Improvement in MISO VLC 77
4.4 PLS for Multiuser VLC 80
4.4.1 Precoding Designs 80
4.4.2 PLS for NOMA-Based VLC 84
4.5 PLS for VLC with Emerging Technologies 86
4.6 Open Challenges and Future Works 90
References 92
5 The Impact of Secrecy on Stable Throughput and Delay 99
Parthajit Mohapatra and Nikolaos Pappas
5.1 Introduction 99
5.1.1 Related Works 100
5.2 System Model 101
5.3 Stability Region for the General Case 103
5.3.1 First Dominant System 103
5.3.2 Second Dominant System 104
5.4 Stability Region Analysis: Receivers with Different Decoding Abilities 105
5.4.1 Receivers with Limited Decoding Abilities 106
5.4.1.1 When Only the Second Queue Is Non-empty 106
5.4.1.2 When Only the First Queue Is Non-empty 106
5.4.1.3 When Both the Queues Are Non-empty 107
5.4.2 Receiver 1 with Limited Decoding Ability and Receiver 2 Uses SD 109
5.5 Impact of Secrecy on Delay Performance 109
5.5.1 Delay Analysis for User with Confidential Data 109
5.6 Results and Discussion 110
5.6.1 Stability Region with Secrecy Constraint 111
5.6.2 Impact of Imperfect Self-interference Cancelation on the Stability Region 112
5.6.3 Impact of Secrecy on Delay 112
5.7 Conclusion 114
References 114
6 Physical-Layer Secrecy for Ultrareliable Low-Latency Communication 117
Parthajit Mohapatra and Nikolaos Pappas
6.1 Introduction 117
6.2 Background 118
6.2.1 Finite Block-Length Information Theory 118
6.2.1.1 Results for the AWGN Channel 119
6.2.1.2 Results for the AWGN Wiretap Channel 119
6.2.1.3 Stability Criteria of a Queue 119
6.2.1.4 Age of Information 119
6.2.2 Related Works 120
6.3 System Model 121
6.4 Impact of Secrecy on Stable Throughput 122
6.5 Impact of Secrecy on Latency 125
6.5.1 Delay Analysis 125
6.5.2 AAoI Analysis 126
6.6 Results and Discussion 126
6.7 Conclusion 130
References 130
Part III Integration of Physical-layer Security with 6g Communication 133
7 Security Challenges and Solutions for Rate-Splitting Multiple Access 135
Abdelhamid Salem and Christos Masouros
7.1 Introduction 135
7.2 Security Issues in RSMA 137
7.3 How Much of the Split Signal Should Be Revealed? 138
7.3.1 Ergodic Rates 140
7.3.2 Power Allocation Strategy for Secure RSMA Transmission 142
7.4 Secure Beamforming Design for RSMA Transmission 146
7.4.1 Optimization Framework 147
7.4.1.1 Perfect CSIT 147
7.4.1.2 Imperfect CSIT 148
7.5 Conclusion 150
References 151
8 End-to-End Autoencoder Communications with Optimized Interference Suppression 153
Kemal Davaslioglu, Tugba Erpek, and Yalin Sagduyu
8.1 Introduction 153
8.2 Related Work 156
8.3 System Model 157
8.4 Performance Evaluation of AEC Considering the Effects of Channel, Quantization, and Embedded Implementation 159
8.4.1 Comparison of Signal Constellations 160
8.4.2 Effects of EVM 163
8.4.3 Effects of Quantization 163
8.4.4 Practical Considerations for Embedded Devices 164
8.5 Data Augmentation to Train the AE Model Using GANs 166
8.5.1 BER Performance with GAN-Based Data Augmentation 168
8.6 Methods to Suppress the Effects of Interference 169
8.7 AE Communications with Interference Suppression for MIMO Systems 177
8.8 Conclusion 179
References 179
9 AI/ML-Aided Processing for Physical-Layer Security 185
Muralikrishnan Srinivasan, Sotiris Skaperas, Mahdi Shakiba Herfeh, and Arsenia Chorti
9.1 Introduction 185
9.1.1 Facilitating the Incorporation of PLS in 6G 186
9.2 Proposed Metrics for RF Fingerprinting and SKG 187
9.2.1 Total Variation Distance for Radio Frequency Fingerprinting 187
9.2.2 Cross Correlation for SKG 188
9.2.3 Statistical Independence Metric 189
9.2.4 Reciprocity and Mismatch Probability 190
9.3 Power Domain Preprocessing 190
9.3.1 Preprocessing Using PCA 192
9.3.2 Preprocessing Using AEs 195
9.4 Conclusions 198
References 198
10 Joint Secure Communication and Sensing in 6G Networks 203
Miroslav Mitev, Amitha Mayya, and Arsenia Chorti
10.1 Introduction 203
10.2 Related Work and Motivation 205
10.3 System Model 206
10.4 Secret Key Generation Protocol 207
10.4.1 Advantage Distillation 207
10.4.2 Information Reconciliation 208
10.4.3 Privacy Amplification 209
10.5 Measurement Setup 209
10.5.1 Scenarios 210
10.5.2 Implementation of the SKG Protocol 211
10.6 Results and Discussion 212
Acknowledgments 218
References 218
Part IV Applications 221
11 Physical-Layer Authentication for 6G Systems 223
Stefano Tomasin, He Fang, and Xianbin Wang
11.1 Authentication by Physical Parameters 223
11.1.1 PLA and 6G Systems 225
11.2 Challenge-Response PLA for 6G 226
11.3 Intelligent PLA Based on Machine Learning 229
11.3.1 Machine-Learning-Based PLA Approach 231
11.3.2 Performance Analysis 232
References 235
12 Securing the Future e-Health: Context-Aware Physical-Layer Security 239
Mehdi Letafati, Eduard Jorswieck, and Babak Khalaj
12.1 Introduction 239
12.1.1 PHYSEC in 6G 239
12.1.2 Introduction to PHYSEC Solutions 241
12.1.2.1 General Model and Problem Formulations 241
12.1.2.2 Key-less Versus Key-Based Techniques 243
12.1.2.3 Active and Passive Attacks 244
12.2 PHYSEC Key Generation 245
12.2.1 Learning-Aided PHYSEC for e-Health 246
12.2.1.1 Neural Network Implementation 248
12.2.1.2 Information-Theoretic Secrecy Analysis 250
12.2.2 Covert or Stealthy SKG 251
12.2.3 SKG in Multiuser Massive MIMO 252
12.2.4 Robust MiM Attack-Resistant SKG for Multi-carrier MIMO Systems 255
12.3 Key-less PHYSEC for Medical Image Transmission 258
12.3.1 Content- and Delay-Aware Design 259
12.3.1.1 Security Level Adjustment 261
12.3.1.2 Evaluations 262
12.4 Proof-of-Concept Study 263
12.5 Conclusions and Future Directions 266
References 267
13 The Role of Non-terrestrial Networks: Features and Physical-Layer Security Concerns 275
Marco Giordani, Francesco Ardizzon, Laura Crosara, Nicola Laurenti, and Michele Zorzi
13.1 Non-terrestrial Networks for 6G 275
13.1.1 Use Cases 277
13.1.1.1 Continuous and Ubiquitous Network Coverage 277
13.1.1.2 Support for the Internet of Things 277
13.1.1.3 Integration Between Communication and Computation 278
13.1.1.4 Energy-Efficient Service 278
13.1.2 Enabling Technologies 278
13.1.2.1 Novel Network Solutions 278
13.1.2.2 Novel Antenna Solutions 279
13.1.2.3 Novel Spectrum Solutions 279
13.1.3 Open Research Questions 279
13.1.3.1 Physical-Layer Procedures 279
13.1.3.2 Synchronization 280
13.1.3.3 Channel Estimation and Random Access 280
13.1.3.4 Mobility Management 280
13.1.3.5 Resource Saturation 281
13.1.3.6 Higher-Layer Protocol (Re)design 281
13.1.3.7 The Role of the Uplink 282
13.1.3.8 Security and Privacy 282
13.2 Physical-Layer Security in Non-terrestrial Networks 282
13.2.1 Physical-Layer Secrecy in NTNs 283
13.2.1.1 Two-Way Protocols 284
13.2.1.2 Geographical Constraints 284
13.2.1.3 Use of Relays and Friendly Jamming Helpers 285
13.2.2 Physical-Layer Authentication for NTNs 285
13.2.2.1 Device-Based PLA 287
13.2.2.2 Channel-Based PLA 288
13.2.2.3 Challenges and Future Works for PLA 289
13.2.3 Position Integrity for NTNs 290
13.2.3.1 System Model 291
13.2.3.2 Attack Model 293
13.2.3.3 Authentication Procedure 294
13.2.3.4 Performance Metrics 295
13.3 Conclusions 298
References 299
14 Quantum Hardware-Aware Security for 6G Networks 305
Matthias Frey, Igor BjelakoviÄ, Janis N¶tzel, Juliane Kr¤mer, and SÅawomir StaÅczak
14.1 Introduction 305
14.2 Preliminaries 308
14.2.1 Quantum States and Observables 308
14.2.2 Quantum Channels 309
14.2.3 Bosonic Systems 311
14.2.4 Information Measures 312
14.3 Secret Communication 312
14.3.1 Semantic Security and Its Operational Significance 313
14.3.2 Other Security Measures Used in the Analysis of Secret Communication 315
14.3.3 Survey of Results 316
14.3.3.1 Finite-Dimensional Case 317
14.3.3.2 Infinite-Dimensional Case 318
14.4 Covert Communication 320
14.4.1 System Model 321
14.4.2 Survey of Results 323
14.5 Conclusion 325
Acknowledgments 326
References 326
15 Leveraging the Physical Layer to Achieve Practically Feasible Confidentiality and Authentication 331
Marco Baldi and Linda Senigagliesi
15.1 Introduction 331
15.2 System Model 332
15.3 Confidentiality at the Physical Layer in Practical Settings 335
15.3.1 Joining Physical-Layer Security with Cryptography 336
15.3.2 Dealing with Variable Channel Quality Through Onâ"Off Transmissions 338
15.4 Authentication at the Physical Layer in Practical Settings 342
15.4.1 PLA Metrics 344
15.5 Numerical Experiments 345
15.5.1 Physical-Layer Confidentiality Examples 345
15.5.2 Physical-Layer Authentication Examples 347
15.6 Conclusion 351
References 351
Index 355
