Quantum Communications and Cryptography (Optical Science and Engineering)

All current methods of secure communication such as public-key cryptography can eventually be broken by faster computing. At the interface of physics and computer science lies a powerful solution for secure communications: quantum cryptography. Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. This allows for totally secure random key distribution, a central requirement for use of the one-time pad. Since the one-time pad is theoretically proven to be undecipherable, quantum cryptography is the key to perfect secrecy. Quantum Communications and Cryptography is the first comprehensive review of the past, present, and potential developments in this dynamic field. Leading expert contributors from around the world discuss the scientific foundations, experimental and theoretical developments, and cutting-edge technical and engineering advances in quantum communications and cryptography. The book describes the engineering principles and practical implementations in a real-world metropolitan network as well as physical principles and experimental results of such technologies as entanglement swapping and quantum teleportation. It also offers the first detailed treatment of quantum information processing with continuous variables. Technologies include both free-space and fiber-based communications systems along with the necessary protocols and information processing approaches. Bridging the gap between physics and engineering, Quantum Communications and Cryptography supplies a springboard for further developments and breakthroughs in this rapidly growing area. Front Cover......Page 1 Preface......Page 6 Editor......Page 10 Contributors......Page 12 Contents......Page 16 1. Quantum Cryptography......Page 18 2. Quantum Communications with Optical Fibers......Page 34 3. Advanced Quantum Communications Experiments with Entangled Photons......Page 62 4. The DARPA Quantum Network......Page 100 5. Experimental Cryptography Using Continuous Polarization States......Page 120 6. Quantum Logic Using Linear Optics......Page 144 7. Practical Quantum Cryptography: Secrecy Capacity and Privacy Amplification......Page 162 8. Quantum State Sharing......Page 180 9. Free-Space Quantum Cryptography......Page 204 10. Noise-Immune Quantum Key Distribution......Page 228 Index......Page 242 "For graduate physics and engineering students, and researchers and engineers in telecommunications, specialists in those fields offer a general overview of scientific foundations, theoretical and experimental results, and specific technological and engineering developments in quantum communication and quantum cryptography that have been demonstrated in university and government research laboratories around the world." -- Publisher