Quantum cryptography
hideQuantum cryptography, or quantum key distribution (QKD), uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random bit string known only to them, which can be used as a key to encrypt and decrypt messages.
An important and unique property of quantum cryptography is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about), otherwise no secure key is possible and communication is aborted.
The security of quantum cryptography relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping or guarantee of key security.
Quantum cryptography is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key.
For more information about Quantum cryptography, read the full article at
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News tagged with quantum cryptography
Field experiment on a robust hierarchical metropolitan quantum cryptography network
Oct 16, 2009 |
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Key Laboratory of Quantum Information (CAS), University of Science and Technology of China has recently demonstrated a metropolitan Quantum Cryptography Network (QCN) for Government Administration in Wuhu, China. The project ...
Up-scale: Frequency converter enables ultra-high sensitivity infrared spectrometry
Aug 26, 2009 |
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In what may prove to be a major development for scientists in fields ranging from forensics to quantum communications, researchers at the National Institute of Standards and Technology have developed a new, ...
Researchers unite to distribute quantum keys
Jul 02, 2009 |
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Researchers from across Europe have united to build the largest quantum key distribution network ever built. The efforts of 41 research and industrial organisations were realised as secure, quantum encrypted information ...
Scientists demonstrate all-fiber quantum logic
May 28, 2009 |
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A team of physicists and engineers have demonstrated all-fibre quantum logic, where single photons are generated and used to perform the controlled-NOT quantum logic gate in optical fibres with high fidelity.
Austrian breakthrough in quantum cryptography: Record in the transmission of entangled photon pairs (Update)
May 03, 2009 |
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Austrian physicists say a breakthrough in next-generation quantum cryptography could allow encrypted messages to be bounced off satellites, the British journal Nature reported Sunday.
Making quantum cryptography practical
Apr 30, 2009 |
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Quantum cryptography, a completely secure means of communication, is much closer to being used practically as researchers from Toshiba and Cambridge University's Cavendish Laboratory have now developed high speed detectors ...
Scientists demonstrate laser with controlled polarization
Apr 13, 2009 |
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Applied scientists at the Harvard School of Engineering and Applied Sciences (SEAS) in collaboration with researchers from Hamamatsu Photonics in Hamamatsu City, Japan, have demonstrated, for the first time, ...
Trading carats for nanometers - and defective diamonds for crystal clear microscopy
Mar 02, 2009 |
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(PhysOrg.com) -- Large, perfect diamonds are precious to almost all of us but to some scientists, it is the defects that really matter. This is because defects can form nanoscopic color centers, which play ...
World first for sending data using quantum cryptography
Oct 08, 2008 |
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(PhysOrg.com) -- For the first time the transmission of data secured by quantum cryptography is demonstrated within a commercial telecommunications network. 41 partners from 12 European countries, including ...
Light touch: Controlling the behavior of quantum dots
Aug 19, 2008 |
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Researchers from the National Institute of Standards and Technology and the Joint Quantum Institute (JQI), a collaborative center of the University of Maryland and NIST, have reported a new way to fine-tune ...
Vegas 'Quantum Spookshow' Demos On-the-Fly Encryption of Streaming Video
Aug 06, 2008 |
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Las Vegas shows often are on the cutting edge. Following this tradition, researchers from the National Institute of Standards and Technology (NIST) and their colleagues at the National University of Singapore (NUS) have landed ...
Siemens builds a lock made of light: Data transfer using quantum cryptography
Aug 01, 2008 |
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(PhysOrg.com) -- Electronic communication is becoming more secure all over the world. Siemens IT Solutions and Services, Austrian Research Centers (ARC) and Graz University of Technology have joined forces ...
