The Unclonable Photon (Hardcover)

Hardcover. Every classical signal can be copied. A single photon cannot. That one law of nature, the no-cloning theorem, is the foundation of a new kind of security, and The Unclonable Photon shows, equation by equation and device by device, how engineers turn it into working quantum networks.The book begins with a simple question: what must a secret key be? From there it builds the quantum toolkit step by step, from density operators, channels and measurements to the no-cloning theorem and Bell's inequality, and proves the existence of the photon itself with the Hanbury Brown-Twiss experiment. It then descends into real hardware: lasers and their rate equations, modulators, optical fibres, phonons and Raman noise, single-photon detectors, and how to read and verify their datasheets.Every major protocol is derived in detail, from BB84, six-state and SARG04 to DPS, COW, MDI, twin-field, continuous-variable and device-independent QKD, with realistic finite-key numbers rather than brochure figures. Repeaters, satellites, trusted-node networks and hybrid post-quantum systems complete the picture.With more than 170 worked problems, ten design case studies and seven laboratory exercises, this is a book for engineers, physicists and security architects who want to understand not only why quantum communication is secure, but what it really takes to build. This item is printed on demand. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.…