This book focuses on techniques that can be applied at the physical and data-link layers of communication systems in order to secure transmissions against eavesdroppers. It discusses topics ranging from information theory-based security to coding for security and cryptography, and presents cutting-edge research and innovative findings from leading researchers. The characteristic feature of all the contributions in this book is their relevance for the practical application of security principles to a variety of widely used communication techniques, including: multiantenna systems, ultra-wide-band communication systems, power line communications, and quantum key distribution techniques. A further distinctive aspect is the attention paid to both unconditional and computational security techniques, building a bridge between two usually distinct worlds. The book gathers extended versions of contributions delivered at the Second Workshop on Communication Security, held in Paris, France, in April 2017 and affiliated with the conference EUROCRYPT 2017.

This book focuses on techniques that can be applied at the physical and data-link layers of communication systems in order to secure transmissions against eavesdroppers. Topics ranging from information theory-based security to coding for security and cryptography are discussed, with presentation of cutting-edge research and innovative results from leading researchers. The characteristic feature of all the contributions is their relevance for practical embodiments: detailed consideration is given to applications of security principles to a variety of widely used communication techniques such as multiantenna systems, ultra-wide band communication systems, power line communications, and quantum key distribution techniques. A further distinctive aspect is the attention paid to both unconditional and computational security techniques, providing a bridge between two usually distinct worlds. The book comprises extended versions of contributions delivered at the Workshop on Communication Security, held in Ancona, Italy, in September 2014 within the framework of the research project "Enhancing Communication Security by Cross-layer Physical and Data-link Techniques", funded by the Italian Ministry of Education, Universities, and Research.

This book focuses on techniques that can be applied at the physical and data-link layers of communication systems in order to secure transmissions against eavesdroppers. It discusses topics ranging from information theory-based security to coding for security and cryptography, and presents cutting-edge research and innovative findings from leading researchers. The characteristic feature of all the contributions in this book is their relevance for the practical application of security principles to a variety of widely used communication techniques, including: multiantenna systems, ultra-wide-band communication systems, power line communications, and quantum key distribution techniques. A further distinctive aspect is the attention paid to both unconditional and computational security techniques, building a bridge between two usually distinct worlds. The book gathers extended versions of contributions delivered at the Second Workshop on Communication Security, held in Paris, France, in April 2017 and affiliated with the conference EUROCRYPT 2017.

This book focuses on techniques that can be applied at the physical and data-link layers of communication systems in order to secure transmissions against eavesdroppers. Topics ranging from information theory-based security to coding for security and cryptography are discussed, with presentation of cutting-edge research and innovative results from leading researchers. The characteristic feature of all the contributions is their relevance for practical embodiments: detailed consideration is given to applications of security principles to a variety of widely used communication techniques such as multiantenna systems, ultra-wide band communication systems, power line communications, and quantum key distribution techniques. A further distinctive aspect is the attention paid to both unconditional and computational security techniques, providing a bridge between two usually distinct worlds. The book comprises extended versions of contributions delivered at the Workshop on Communication Security, held in Ancona, Italy, in September 2014 within the framework of the research project "Enhancing Communication Security by Cross-layer Physical and Data-link Techniques", funded by the Italian Ministry of Education, Universities, and Research.

This book constitutes the refereed and revised post-conference proceedings of the 8th International Workshop on Code-Based Cryptography, CBCrypto 2020, held in Zagreb, Croatia, in May 2020.*The seven papers presented in this book were carefully reviewed and selected from numerous submissions. These contributions focus on various topics such as code-based cryptography, from design to implementation, security, new systems, and improved decoding algorithms. * The conference was held virtually due to the COVID-19 pandemic.

This book constitutes the refereed and revised post-conference proceedings of the 7th International Workshop on Code-Based Cryptography, CBC 2019, held in Darmstadt, Germany, in May 2019. The eight papers presented in this book were carefully reviewed and selected from numerous submissions. These contributions are divided into two groups: The first four papers deal with the design of code-based cryptosystems, while the following four papers are on cryptanalysis of code-based cryptosystems.

This book describes the fundamentals of cryptographic primitives based on quasi-cyclic low-density parity-check (QC-LDPC) codes, with a special focus on the use of these codes in public-key cryptosystems derived from the McEliece and Niederreiter schemes. In the first part of the book, the main characteristics of QC-LDPC codes are reviewed, and several techniques for their design are presented, while tools for assessing the error correction performance of these codes are also described. Some families of QC-LDPC codes that are best suited for use in cryptography are also presented. The second part of the book focuses on the McEliece and Niederreiter cryptosystems, both in their original forms and in some subsequent variants. The applicability of QC-LDPC codes in these frameworks is investigated by means of theoretical analyses and numerical tools, in order to assess their benefits and drawbacks in terms of system efficiency and security. Several examples of QC-LDPC code-based public key cryptosystems are presented, and their advantages over classical solutions are highlighted. The possibility of also using QC-LDPC codes in symmetric encryption schemes and digital signature algorithms is also briefly examined.