Quantum teleportation, key distribution, and practical quantum cryptography

Rajendra Kumar Bera

Arindam Mitra

Existing quantum key distribution protocols require classical channel and classical authentication procedure. We present an alternative quantum key distribution technique which not only can operate without the requirement of classical channel and classical authentication procedure but also rejects the use of the two. This key distribution technique can act as quantum authentication protocol. Quantum cryptography [1-6] and teleportation [7] are the two facets of quantum communication. Of these two, quantum cryptography has been developed out of practical necessity- classical cryptosytems are either secure but impractical or insecure but practical [8]. Around 1970, Wiesner [1] first realised that laws of quantum mechanics can ensure security. In 1984, this radical idea took shape when Bennett and Brassad [2] invented quantum key distribution (QKD) protocol. At present many QKD protocols exist; they can be classified as EPR and non EPR protocols. The common aspects of all these protocols are that pure

K. I. Hajim, Sheelan Kh. Tawfiq, Ahmed M. Meki

In this article, a short review on the feature of reality and locality in quantum optics is given.The Bell inequality and the Bell states are introduced to show their direct use in quantum computer andquantum teleportation. Moreover, quantum cryptography is discussed in some details regarding basicideas and practical considerations. In addition, a case study involving distillation of a quantum key basedon the given fundamentals is presented and discussed.

Andreas Poppe, Alessandro Fedrizzi, Hannes Hübel +2 more

Christopher C. Gerry, Kimberley M. Bruno

This chapter discusses quantum information science (QIS), quantum key distribution (QKD), and quantum teleportation. The new field of QIS encompasses several overlapping subdisciplines: quantum computing, quantum key distribution (also known as quantum cryptography), and quantum metrology (the measurement of small parameters and weak forces with ultra-high precision). In QIS, bits of information are encoded in quantum states, which themselves can be in superposition states and/or entanglement states. Generically, the 0 and 1 quantum bits are represented as qubits (quantum bits). QKD, or quantum cryptography, is a completely secure method of secret communication, and will remain so even if a quantum computer becomes available. Quantum teleportation is one of the more exotic features to have emerged from the field of QIS. It refers to the ability to transfer an unknown quantum state from one location to another, possibly very distant, location by using quantum entanglement.