Quantum communication system without polarization feedback and quantum secure direct communication method

Abstract

The invention relates to a quantum communication system without polarization feedback and a quantum secure direct communication method. The quantum communication system comprises a communication receiving module, a communication sending module and a quantum channel between the communication receiving module and the communication sending module. A first phase modulator in the communication receiving module can prepare photons at four phases randomly for the communication sending module, and a single-photon detector obtains a quantum bit by detecting the photons returned by the communication sending module; the communication sending module comprises a coding light path module and a security detection module. According to the invention, the consistency of the coding light path and the stability of the security detection light path are utilized, the influence of polarization drift caused by birefringence is avoided, the coding light path realizes polarization drift self-compensation, the bit error rate of quantum bits is reduced, and the communication quality is improved.

Description

technical field [0001] The invention relates to the technical field of quantum information, in particular to a quantum communication system without polarization feedback and a quantum safe direct communication method. Background technique [0002] Quantum secure direct communication is a new type of communication mode proposed by Long Guilu et al. in 2002. It breaks the traditional dual-channel model, and the communication parties only use one quantum channel to transmit information. Quantum secure direct communication is a combination of classical coding theory and eavesdropping channel theory. It does not need to use quantum memory, nor does it need to generate keys to encrypt information, and it realizes efficient, real-time, and safe information transmission. [0003] Quantum-safe direct communication needs to meet two requirements: 1. After the communication receiver receives the quantum state as the information carrier, it can directly read the confidential information...

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Problems solved by technology

[0007] In view of this, the technical problem to be solved by the present invention is how to provide a quantum communication system without polarization feedback and a quantum safe direct communication method to solve the need for manual modulation and operation of polarization drift in existing quantum safe direct communication. difficult problem

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