Multi-user qkd network system and key distribution method based on m‑z interferometer

Abstract

The invention discloses a multiuser QKD network system based on an M-Z interferometer, and a secret key distribution method thereof. The system comprises a mesh network structure unit and N M-Z type quantum secret key distribution units. The mesh network structure unit comprises public fibers, wavelength router devices and special-purpose fibers. One port of any one wavelength router apparatus is connected with one public fiber and is respectively correspondingly connected with other wavelength router devices through the special-purpose fibers. The N M-Z type quantum secret key distribution units are connected with the mesh network structure unit through the public fibers, and any one M-Z type quantum secret key distribution unit can communicate with other M-Z type quantum secret key distribution units through the mesh network structure unit, such that simultaneous communication among users is realized. The system provided by the invention is simple in integral structure, realizes intercommunication between any two users and among N users, is less influenced by an increase of the user number in terms of single-channel performance, and has quite good full-network expansibility and security.

Description

technical field [0001] The invention relates to the field of quantum communication and optical fiber communication network, in particular to a multi-user QKD network system based on an M-Z interferometer and a key distribution method thereof. Background technique [0002] Traditional cryptography mainly guarantees its security through mathematical calculation complexity, but with the current progress and improvement of computing power, the security of traditional cryptography is under great threat. The security of quantum cryptography does not depend on the complexity of calculations, but is based on the basic principles of quantum mechanics, namely the Heisenberg uncertainty principle and the principle that unknown quantum states cannot be cloned. Quantum Key Distribution (QKD) can allow legitimate participants in different geographical locations to share keys in an absolutely secure manner. The key transmission channel of both parties can be free space or optical fiber, an...

AI Technical Summary

Problems solved by technology

Common types of typical QKD network networking schemes include network topologies such as mesh, tree, ring, bus, and mesh. It can be found that the mesh and tree QKD network topology schemes have relatively simple structures , the network performance has an advantage in the case of a small number of users, but it is difficult to give full play to its advantages in a multi-user environment; the ring network has the advantage of low cost, but it has no advantages in link interruption failures and security caused by noise; the bus The type has certain advantages in its security and convenience, but with the increase of users, signal degradation will occur;

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