Cover13; -- Preface -- Acknowledgements -- Table of Contents 13; -- 1 Introduction -- 1.1 Security Requirements of Communication -- 1.2 Overview of Quantum Private Communication -- 1.3 Private Communication Models -- 1.3.1 Classic Secure Communication Model -- 1.3.2 Quantum Private Communication Model -- 1.4 History of Quantum Private Communication -- 1.5 Relationship with Other Subjects -- 1.6 Notations and Conventions -- 1.6.1 Random Variables -- 1.6.2 Cryptosystem and Cipher -- References -- 2 Quantum Security Theory -- 2.1 Introduction -- 2.2 Mathematical Background -- 2.2.1 Hilbert Space -- 2.2.2 Properties of Hilbert Space -- 2.2.3 Operators -- 2.2.4 Several Important Operators -- 2.2.5 Matrices Decomposition -- 2.3 Introduction to Quantum Mechanics -- 2.3.1 Quantum Systems -- 2.3.2 Dynamic Characteristics of Quantum Systems -- 2.3.3 Information Retrieval of Quantum Systems -- 2.3.4 Fundament of Quantum Optics -- 2.4 Introduction to Information Theory -- 2.4.1 Entropy -- 2.4.2 Mutual Information -- 2.4.3 Quantum Fano Inequality -- 2.5 Introduction to Complexity Theory -- 2.5.1 Turing Machine -- 2.5.2 Classic Complexity -- 2.5.3 Quantum Complexity -- 2.6 Security Model -- 2.6.1 Information-theoretic Security -- 2.6.2 Computational Security -- 2.6.3 Attack Strategy Analysis -- References -- 3 Quantum Bits -- 3.1 Classic Bits -- 3.2 Quantum Bit Definition -- 3.2.1 Binary Qubit -- 3.2.2 P-ary Qubit -- 3.2.3 Composite Qubit -- 3.3 Quantum Bit Transformation -- 3.3.1 Quantum Logic Gates -- 3.3.2 Quantum Circuits -- 3.4 Mathematical Property -- 3.4.1 Bloch Sphere -- 3.4.2 Orthogonality of Opposite Points -- 3.4.3 Rotations on Bloch Sphere -- 3.5 Physical Property -- 3.5.1 Superposition -- 3.5.2 Entanglement -- 3.5.3 Distinguishability -- 3.5.4 Quantum No-cloning -- 3.6 Information Property -- 3.6.1 Single Qubit Information -- 3.6.2 Nonorthogonal Qubits Information -- References -- 4 Quantum Key Distribution -- 4.1 Intuition on QKD -- 4.2 Standard QKD Schemes -- 4.2.1 BB84 Protocol -- 4.2.2 B92 Protocol -- 4.3 Quantum Communication Model for QKD -- 4.3.1 Quantum Source -- 4.3.2 Quantum Channel -- 4.3.3 Quantum Sink -- 4.4 Reconciliation -- 4.4.1 Reconciliation Model -- 4.4.2 Binary Reconciliation Protocol -- 4.4.3 Non-Binary Reconciliation Protocol -- 4.5 Privacy Amplification -- 4.5.1 Privacy Amplification Principle -- 4.5.2 Privacy Amplification Techniques -- 4.6 Security Model for QKD -- 4.6.1 Security Theory -- 4.6.2 Typical Attack Strategies -- References -- 5 Quantum Cryptosystem -- 5.1 Introduction -- 5.2 QKD-based Cryptosystem -- 5.3 Quantum Vernam Cipher -- 5.3.1 Classic Vernam Algorithm -- 5.3.2 Quantum Vernam Cipher -- 5.3.3 Private Quantum Channel -- 5.3.4 Security Model -- 5.4 Typical Quantum Vernam Ciphers -- 5.4.1 Classic-key-based Quantum Vernam Cipher -- 5.4.2 Bell-key-based Quantum Vernam Cipher -- 5.4.3 Teleportation as Quantum Vernam Cipher -- 5.5 Quantum Block Cipher -- 5.5.1 Theoretical Model -- 5.5.2 Quantum Block Algorithm for Binary Bits -- 5.6 Quantum Public Key Cryptosystem -- 5.7 Typical Quantum Public-key Algorithms -- 5.7.1 Algorithm based Subset-sum Problem -- 5.7.2 Algorithm based.