About the Editors -- List of Contributors -- Preface -- Part I Preliminaries -- 1 Foundations of Physical-Layer Security for 6G 3 Matthieu Bloch -- 1.1 Coding Mechanisms -- 1.1.1 Channel Coding -- 1.1.2 Soft Covering -- 1.1.3 Source Coding with Side Information -- 1.1.4 Privacy Amplification -- 1.2 Coding for Physical-Layer Security -- 1.2.1 Secure Communication -- 1.2.2 Secret-Key Generation -- 1.3 Engineering and Learning Channels -- References -- 2 Coding Theory Advances in Physical-Layer Secrecy 19 Laura Luzzi -- 2.1 Introduction -- 2.2 Wiretap Coding Schemes Based on Coset Coding -- 2.2.1 LDPC Codes for Binary Erasure Wiretap Channels -- 2.2.2 Polar Codes for Binary Input Symmetric Channels -- 2.2.3 Lattice Codes for Gaussian and Fading Wiretap Channels -- 2.3 Wiretap Coding Schemes Based on Invertible Extractors -- 2.3.1 Secrecy Capacity-Achieving Codes for the Gaussian Channel -- 2.4 Finite-Length Results -- References -- Part II Physical-Layer Security in Emerging Scenarios -- 3 Beamforming Design for Secure IRS-Assisted Multiuser MISO Systems 45 Dongfang Xu, Derrick Wing Kwan Ng, and Robert Schober -- 3.1 Introduction -- 3.2 System Model -- 3.3 Resource Allocation Optimization Problem -- 3.3.1 Performance Metrics of Secure Communication -- 3.3.2 Problem Formulation -- 3.4 Solution of the Optimization Problem -- 3.4.1 Problem Reformulation -- 3.4.2 Successive Convex Approximation -- 3.4.3 Complex Circle Optimization -- 3.4.3.1 Tangent Space -- 3.4.3.2 Riemannian Gradient -- 3.5 Experimental Results -- 3.5.1 Average SSR Versus BS Power Budget -- 3.5.2 Average SSR Versus Number of Legitimate Users -- 3.6 Conclusion -- 3.7 Future Extension -- References -- 4 Physical-Layer Security for Optical Wireless Communications 67 Shenjie Huang, Mohammad Dehghani Soltani, and Majid Safari -- 4.1 Introduction -- 4.2 PLS for SISO VLC -- 4.2.1 PLS Performance Metrics -- 4.2.2 SISO VLC Secrecy Analysis -- 4.3 PLS for MISO VLC -- 4.3.1 MISO VLC Secrecy Analysis -- 4.3.2 Secrecy Improvement in MISO VLC -- 4.4 PLS for Multiuser VLC -- 4.4.1 Precoding Designs -- 4.4.2 PLS for NOMA-Based VLC -- 4.5 PLS for VLC with Emerging Technologies -- 4.6 Open Challenges and Future Works -- References -- 5 The Impact of Secrecy on Stable Throughput and Delay 99 Parthajit Mohapatra and Nikolaos Pappas -- 5.1 Introduction -- 5.1.1 Related Works -- 5.2 System Model -- 5.3 Stability Region for the General Case -- 5.3.1 First Dominant System -- 5.3.2 Second Dominant System -- 5.4 Stability Region Analysis: Receivers with Different Decoding Abilities -- 5.4.1 Receivers with Limited Decoding Abilities -- 5.4.1.1 When Only the Second Queue Is Non-empty -- 5.4.1.2 When Only the First Queue Is Non-empty -- 5.4.1.3 When Both the Queues Are Non-empty -- 5.4.2 Receiver 1 with Limited Decoding Ability and Receiver 2 Uses SD -- 5.5 Impact of Secrecy on Delay Performance -- 5.5.1 Delay Analysis for User with Confidential Data -- 5.6 Results and Discussion -- 5.6.1 Stability Region with Secrecy Constraint -- 5.6.2 Impact of Imperfect Self-interference Cancelation on the Stability Region -- 5.6.3 Impact of Secrecy on Delay -- 5.7 Conclusion -- References -- 6 Physical-Layer Secrecy for Ultrareliable Low-Latency Communication 117 Parthajit Mohapatra and Nikolaos Pappas -- 6.1 Introduction -- 6.2 Background -- 6.2.1 Finite Block-Length Information Theory -- 6.2.1.1 Results for the AWGN Channel -- 6.2.1.2 Results for the AWGN Wiretap Channel -- 6.2.1.3 Stability Criteria of a Queue -- 6.2.1.4 Age of Information -- 6.2.2 Related Works -- 6.3 System Model -- 6.4 Impact of Secrecy on Stable Throughput -- 6.5 Impact of Secrecy on Latency -- 6.5.1 Delay Analysis -- 6.5.2 AAoI Analysis -- 6.6 Results and Discussion -- 6.7 Conclusion -- References -- Part III Integration of Physical-layer Security with 6g Communication -- 7 Security Challenges and Solutions for Rate-Splitting Multiple Access 135 Abdelhamid Salem and Christos Masouros -- 7.1 Introduction -- 7.2 Security Issues in RSMA -- 7.3 How Much of the Split Signal Should Be Revealed? -- 7.3.1 Ergodic Rates -- 7.3.2 Power Allocation Strategy for Secure RSMA Transmission -- 7.4 Secure Beamforming Design for RSMA Transmission -- 7.4.1 Optimization Framework -- 7.4.1.1 Perfect CSIT -- 7.4.1.2 Imperfect CSIT -- 7.5 Conclusion -- References -- 8 End-to-End Autoencoder Communications with Optimized Interference Suppression 153 Kemal Davaslioglu, Tugba Erpek, and Yalin Sagduyu -- 8.1 Introduction -- 8.2 Related Work -- 8.3 System Model -- 8.4 Performance Evaluation of AEC Considering the Effects of Channel, Quantization, and Embedded Implementation -- 8.4.1 Comparison of Signal Constellations -- 8.4.2 Effects of EVM -- 8.4.3 Effects of Quantization -- 8.4.4 Practical Considerations for Embedded Devices -- 8.5 Data Augmentation to Train the AE Model Using GANs -- 8.5.1 BER Performance with GAN-Based Data Augmentation -- 8.6 Methods to Suppress the Effects of Interference -- 8.7 AE Communications with Interference Suppression for MIMO Systems -- 8.8 Conclusion -- References -- 9 AI/ML-Aided Processing for Physical-Layer Security 185 Muralikrishnan Srinivasan, Sotiris Skaperas, Mahdi Shakiba Herfeh, and Arsenia Chorti -- 9.1 Introduction -- 9.1.1 Facilitating the Incorporation of PLS in 6G -- 9.2 Proposed Metrics for RF Fingerprinting and SKG -- 9.2.1 Total Variation Distance for Radio Frequency Fingerprinting -- 9.2.2 Cross Correlation for SKG -- 9.2.3 Statistical Independence Metric -- 9.2.4 Reciprocity and Mismatch Probability -- 9.3 Power Domain Preprocessing -- 9.3.1 Preprocessing Using PCA -- 9.3.2 Preprocessing Using AEs -- 9.4 Conclusions -- References -- 10 Joint Secure Communication and Sensing in 6G Networks 203 Miroslav Mitev, Amitha Mayya, and Arsenia Chorti -- 10.1 Introduction -- 10.2 Related Work and Motivation -- 10.3 System Model -- 10.4 Secret Key Generation Protocol -- 10.4.1 Advantage Distillation -- 10.4.2 Information Reconciliation -- 10.4.3 Privacy Amplification -- 10.5 Measurement Setup -- 10.5.1 Scenarios -- 10.5.2 Implementation of the SKG Protocol -- 10.6 Results and Discussion -- Acknowledgments -- References -- Part IV Applications -- 11 Physical-Layer Authentication for 6G Systems 223 Stefano Tomasin, He Fang, and Xianbin Wang -- 11.1 Authentication by Physical Parameters -- 11.1.1 PLA and 6G Systems -- 11.2 Challenge-Response PLA for 6G -- 11.3 Intelligent PLA Based on Machine Learning -- 11.3.1 Machine-Learning-Based PLA Approach -- 11.3.2 Performance Analysis -- References -- 12 Securing the Future e-Health: Context-Aware Physical-Layer Security 239 Mehdi Letafati, Eduard Jorswieck, and Babak Khalaj -- 12.1 Introduction -- 12.1.1 PHYSEC in 6G -- 12.1.2 Introduction to PHYSEC Solutions -- 12.1.2.1 General Model and Problem Formulations -- 12.1.2.2 Key-less Versus Key-Based Techniques -- 12.1.2.3 Active and Passive Attacks -- 12.2 PHYSEC Key Generation -- 12.2.1 Learning-Aided PHYSEC for e-Health -- 12.2.1.1 Neural Network Implementation -- 12.2.1.2 Information-Theoretic Secrecy Analysis -- 12.2.2 Covert or Stealthy SKG -- 12.2.3 SKG in Multiuser Massive MIMO -- 12.2.4 Robust MiM Attack-Resistant SKG for Multi-carrier MIMO Systems -- 12.3 Key-less PHYSEC for Medical Image Transmission -- 12.3.1 Content- and Delay-Aware Design -- 12.3.1.1 Security Level Adjustment -- 12.3.1.2 Evaluations -- 12.4 Proof-of-Concept Study -- 12.5 Conclusions and Future Directions -- References -- 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 -- 13.1.1 Use Cases -- 13.1.1.1 Continuous and Ubiquitous Network Coverage -- 13.1.1.2 Support for the Internet of Things -- 13.1.1.3 Integration Between Communication and Computation -- 13.1.1.4 Energy-Efficient Service -- 13.1.2 Enabling Technologies -- 13.1.2.1 Novel Network Solutions -- 13.1.2.2 Novel Antenna Solutions -- 13.1.2.3 Novel Spectrum Solutions -- 13.1.3 Open Research Questions -- 13.1.3.1 Physical-Layer Procedures -- 13.1.3.2 Synchronization -- 13.1.3.3 Channel Estimation and Random Access -- 13.1.3.4 Mobility Management -- 13.1.3.5 Resource Saturation.