Quantum cryptography

Besides quantum computations, entanglement has also been at the core of other active research such as quantum teleportation [32, 33], dense coding [34, 35], quantum communication [36], and quantum cryptography [37]. It is believed that the conceptual puzzles posed by entanglement have now become a physical source of novel ideas that might result in applications. 

D. Bouwmeester, A.K. Ekert, A. Zeilinger, The Physics of Quantum, Information Quantum Cryptography, Quantum Teleportation, Quantum, Computation (Springer, 2000)... 

Vittorio, Salvatore, Quantum Cryptography Privacy Through Uncertainty, released October 2002, http //www.cs.csa.com/hottopics/crypt/oview/... 

Quantum Cryptography Tutorial, http //www.cs.dartmouth.edu/ jford/crypto.html... 

STED microscopy has important applications outside biology as well. For example, it currently is the only method to locally and noninvasively resolve the 3D assembly of packed nanosized colloidal particles [98,99]. In the realm of solid-state physics, STED microscopy has recently imaged densely packed fluorescent color centers in crystals, specifically charged nitrogen vacancy (NV) centers in diamonds [100]. NV centers in diamond have attracted attention, because of their potential application in quantum cryptography and... 

Approximate versions of the translational EPR state, wherein the -function correlations are replaced by finite-width (Gaussian) distributions, have been shown to characterize the quadratures of the two optical-field outputs of parametric down-conversion, or of a fiber interferometer with Kerr nonlinearity. Such states allow for various schemes of continuous-variable quantum information processing such as quantum teleportation [Braunstein 1998 (b) Furu-sawa 1998] or quantum cryptography [Silberhorn 2002], A similar state has also been predicted and realized using collective spins of large atomic samples [Polzik 1999 Julsgaard 2001]. It has been shown that if suitable interaction schemes can be realized, continuous-variable quantum states of the original EPR type could even serve for quantum computation. 

Summarizing, QE and decoherence are not only important for technological applications, like quantum computers and quantum cryptography, but are far more important for condensed matter physics as well as chemistry than it has been realized thus far. 

The preceding formalism of SU(2) phase states can be used in a number of problems of quantum physics. As an illustrative example of great importance, consider the so-called Einstein-Podolsky-Rosen (EPR) paradox [73] (see also discussions in Refs. 14, 15, 74, and 75). The EPR paradox touches on the conceptual problems of reality and locality and existence of hidden variables in quantum physics as well as the more technological aspects of quantum cryptography [34]. 

In contrast to classical cryptographic methods, the security of quantum cryptography is based on the fundamental laws of physics. It is guaranteed by the Heisenberg uncertainty principle and is independent of any mathematical or technological developments. 

The first prototype of quantum cryptographic apparatus came into existence around 1990 [147]. In the meantime, quantum cryptography has become a well-known technique of communication in a provably secure way, and together with an intensive research in the held of quantum computers it has given rise to a whole new branch of science quantum information theory [148]. Viewed from this perspective, quantum cryptography today is only a subset of a broad held of quantum communications that also include quantum teleportation, quantum dense coding, quantum error-correcting codes, and quantum data compression. 

It should be stressed that future practical applications of quantum cryptography are by far not the only benefit of this area of research. As already mentioned, a whole new field has been stimulated, which has helped us better understand the nature. It is believed that this resource is still far from being exhausted. 

D. Mayers, in Advances in Cryptology, Proc. Crypto 96, Springer, Berlin, 1996, p. 343 Los Alamos e-print archive quant-ph/9606003 D. Mayers, Unconditional Security in Quantum Cryptography, Los Alamos e-print archive quant-ph/9802025v4 (1998). 

A problem associated with quenched breakdown operation is light emission from the diode. Light emission can be a problem for correlation experiments and quantum cryptography [299, 515] (see Fig. 5.105, page 175). 

Accessibility of single spins for a manipulation even at room temperature, coherent control and read-out, demonstrated by the investigations of the N-V colour centers, together with the proposals of application of these centers for room temperature single-photon emitters [17], quantum cryptography [18], quantum memory and quantum repeaters [19], puts the diamond-based systems on much more higher level in quantum information race . 

Due to an increasing number of applications, from quantum optics, quantum cryptography and the realization of quantum optical gates, significant efforts have been expended recently in the development of new and reliable single-... 

K. Kuwata, Thermodynamics at the Region where Stability Interferes with Dynamics. Thermodynamics of Quantum Cryptography for Representation of Prion , Netsu Sokutei, 2008, 35, 140. 

Charles Bennett and Gilles Brassard create the quantum cryptography protocol BB84. 

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