QKD system and method based on COW protocol

Abstract

The invention discloses a QKD system and method based on a COW protocol. The QKD system comprises a quantum key coding end and a quantum key decoding end which are connected through a quantum key distribution channel. The quantum key coding end comprises a phase modulation light source. The phase modulation light source codes a light signal based on the COW protocol, thereby outputting double-pulse sequence signal light to the quantum key decoding end through the quantum key distribution channel. When quantum key distribution is carried out, the double-pulse sequence signal light is coded at the quantum key coding end based on the COW protocol and then is sent to the quantum key decoding end through the quantum key distribution channel for decoding, thereby obtaining a corresponding decoding result. According to the QKD system and method provided by the invention, coding and decoding are carried out based on the COW protocol, the basis matching problem is eliminated, the protocol efficiency is high, the light source is modulated by employing a phase, the high efficiency is obtained, and moreover, the QKD system cost problem of COW protocol coding is overcome, thereby facilitating integration and miniaturization of the product.

Description

technical field [0001] The present invention relates to the field of quantum communication, in particular to the technical field of quantum key distribution, and in particular to a QKD system and method based on the COW protocol. Background technique [0002] Secure communication is a communication system that encrypts the code stream of the transmitted information source at the sending end and decrypts and authenticates at the receiving end to prevent information from being disturbed or eavesdropped. It can ensure the security and integrity of the information transmitted by both parties in communication. At present, the RSA public key system is widely used in secure communication. The security of this public key system is guaranteed by the complexity of the algorithm and the limitation of computer computing power. The continuous improvement of modern mathematical computing capabilities and the rapid development of quantum computers have been threatening the security of the ...

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Problems solved by technology

[0004] The COW protocol uses the coherence between any pair of adjacent pulse trains to detect whether there is an eavesdropper. The phase stability of adjacent pulses is the basis for coherence detection. Therefore, the traditional QKD system based on the COW protocol needs to use a narrow The linewidth laser emits continuous light, and the intensity modulator generates pulsed light to ensure the stability of the two adjacent pulse phases. The narrow linewidth continuous laser is expensive and expensive, and it is difficult to be widely used; in addition, the intensity modulator Normal operation requires high-speed electrical signal drive, and the amplitude of the driving electrical signal must reach its half-wave voltage Vπ. In the field of high-speed electronics, the higher the speed and the greater the amplitude, the more difficult it is to generate electrical pulses, so the standard high-speed Driving telecommunications puts forward high requirements on electronics, and the intensity modulator is very sensitive to temperature changes, requiring an additional feedback control system to compensate for the temperature drift of the device itself, increasing the complexity of the system; at the same time, the traditional COW-based protocol It is difficult to integrate and miniaturize when using lasers and intensity modulators together, which limits its application

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