Introduction to Quantum Cryptography

Quantum cryptography is a relatively new field of science, spanning multiple disciplines including physics, computer science, and mathematics. Though originally synonymous with quantum key distribution (QKD), today it consists of many other applications. In the decades since it was originally introduced, research in quantum cryptography has developed rich theoretical and also practical results that promise a communication infrastructure secure against future technological and algorithmic breakthroughs (as opposed to today's public key cryptography which necessarily depends on unproven computational assumptions). Its study has led not only to fascinating insights into general quantum mechanics and information science, but also to the commercialization of quantum secure communication technology, which is being adopted by governments, telecommunication companies, and banks among others. Introduction to Quantum Cryptography introduces readers to the theory of quantum cryptography, with a focus will on quantum key distribution (QKD) as well as more advanced quantum cryptographic protocols beyond QKD. The book also contains a brief introduction to the field of modern cryptography, needed to fully appreciate and understand how quantum cryptographic systems are proven secure and how they can be safely used in combination with current day classical systems. Moving beyond this introductory material, Dr. Krawec introduces readers to quantum key distribution (QKD) - perhaps the most celebrated, and currently the most practical, of quantum cryptographic techniques. Basic protocols are described, and security proofs are given in detail, giving readers the knowledge needed to understand how QKD protocols are proven secure using modern, state of the art, definitions of security in the field. Readers are also introduced to the classical post-processing methods needed to correctly operate QKD protocols. Following this, more advanced QKD protocols are discussed, along with alternative quantum and classical methods to improve QKD performance. Finally, alternative quantum cryptographic protocols are described, along with a discussion on some of the practical considerations of quantum secure communication technology, giving readers a very broad view of the field. Throughout, protocols are described in a clear and consistent manner, while also providing theoretical security proofs and methods.