Quantum key distribution method based on single photon multi-degree of freedom irrelevant to measurement device

Abstract

The present invention provides a quantum key distribution method based on a single photon multi-degree of freedom irrelevant to a measurement device. The method employs spaces and polarization singlephotons to perform coding on a polarization freedom and a space path freedom and sends the spaces and polarization single photons after coding to a third-party measurement device. The third-party measurement device is employed to perform hyper-entangled Bell state analysis to achieve complete distinguishing of 16 Bell states. Compared to a quantum key distribution protocol scheme irrelevant to anoriginal measurement device, the information is encoded on two degrees of freedom, and a non-linear optical condition is employed to perform complete distinguishing of the 16 Bell states so as to effectively utilize the safe keys and improve the channel capacity. Besides, in order to respond to the safety hole of photon number separation attack, a decoy state technology is used. The quantum key distribution method based on a single photon multi-degree of freedom irrelevant to a measurement device can greatly improve the utilization of the code forming rate and the safe keys and can ensure thereliability and the safety of the transmission process.

Description

technical field [0001] The invention relates to quantum communication technology, in particular to a quantum key distribution method. Background technique [0002] Quantum key distribution (QKD) is an important branch of quantum information science, which allows two legitimate users at a distance to share a security key, and if there is an eavesdropping, it can be discovered. In 1984, Charles H. Bennett of IBM Corporation and Gilles Brassard of the University of Montreal proposed the first QKD protocol, the BB84 protocol, which has attracted widespread attention due to its simplicity and efficiency. However, in actual use, due to the imperfection of the equipment, there are still many loopholes in the quantum key system. Attackers known as quantum hackers can target these vulnerabilities by implementing beam-splitting attacks, time-shifting attacks, and blinding attacks to obtain key information. Among them, the detectors were attacked most frequently. [0003] However, t...

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Problems solved by technology

In the middle, the detector was attacked most frequently

[0003] However, the MDI-QKD schemes that have been reported so far only involve a single degree of freedom to increase the security key transmission distance and increase the security key generation rate

However, the existing MDI-QKD scheme encodes information on one degree of freedom, and uses linear optical conditions to implement Bell state measurement, with only a 50% success probability. Therefore, the original MDI-QKD scheme has low coding rate and Disadvantages of small channel capacity

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