Parthajit Mohapatra, PhD, 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, PhD, 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, PhD, 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 IoT networks, and related subjects.

Stefano Tomasin, PhD, 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 EiC of the IEEE Transactions on Information Forensics and Security.

About the Editors xiii List of Contributors xv Preface xix Part I Preliminaries 1 1 Foundations of Physical-Layer Security for 6G 3Matthieu 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 19Laura 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 45Dongfang 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 67Shenjie 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 99Parthajit 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 117Parthajit 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 135Abdelhamid 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 153Kemal 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 185Muralikrishnan 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 203Miroslav 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 223Stefano 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 239Mehdi 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 275Marco 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 305Matthias Frey, Igor Bjelakovi¿, Janis Nötzel, Juliane Krämer, and S¿awomir Stäczak 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 331Marco 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...