Available Technology
Positive-operator-valued measure (POVM) receiver for quantum cryptography
Technology:
Simple quantum-cryptographical system
Markets Addressed
This technology is particularly useful in the security and cryptography industries.
Innovations and Advantages
Quantum cryptography relies on the impossibility of ascribing definite values to non-communicating variables in order to assure secrecy of communication. Theoretical and experimental efforts in this area have been concentrated mainly on one of the basic cryptographic techniques, namely key distribution. Conventional cryptography provides no tools to guarantee the security of the key distribution. Any encoding by means of classical objects is vulnerable to passive interception.
Quantum cryptography cannot prevent eavesdropping, but any eavesdropping attempt can be detected by the legitimate users of the communication channel. This is because eavesdropping affects the quantum state of the information carriers and results in an abnormal error rate. This invention describes the simplest quantum-cryptographical system based on two non-orthogonal states, from the point of view of its robustness to various eavesdropping strategies. In particular, two types or eavesdropping are compared, translucent eavesdropping and opaque eavesdropping, where translucent and opaque refer to the transmitted photons. Also, a technique for estimating the error rate above which the key distribution is deemed unsafe and should be abandoned.
Additional Information
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Inventor(s):
Brandt, Howard E.
Myers, John
Categories:
For further information, please contact:
Gwen Miner, Director of Business Development
(617) 495-3067
Reference Harvard Case #1351