Parthajit Mohapatra & Nikolaos Pappas 
Physical-Layer Security for 6G [PDF ebook] 

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 AAo I 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 Mi M 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 Bjelaković, Janis Nötzel, Juliane Krämer, and Sławomir Stańczak

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 On–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

Parthajit Mohapatra, Ph D, is Associate Professor in the Department of Electrical Engineering, Indian Institute of Technology, India. His research focuses on physical-layer secrecy, short packet communication, union of networking & physical-layer techniques, and related areas.
Nikolaos Pappas, Ph D, is Associate Professor in the Department of Computer and Information Science, Linköping University, Sweden. His research concerns semantic wireless communications, network-level cooperative wireless networks, stochastic modeling, and related subjects.
Arsenia Chorti, Ph D, is Professor and Head of the Information, Communications and Imaging (ICI) Group of the ETIS Lab UMR8051, CY Cergy Paris Universite, France, and a Visiting Research Scholar at Princeton University, USA, and the University of Essex, UK. Her research focuses on physical-layer security, especially context-aware security, intrusion detection in Io T networks, and related subjects.
Stefano Tomasin, Ph D, is Professor at the University of Padova, Italy. His research concerns physical-layer security and signal processing for wireless communications, and he serves as Deputy Ei C of the IEEE Transactions on Information Forensics and Security.