Multi-user measurement equipment unrelated QKD system and method based on GHZ entangled state

Abstract

The invention provides a multi-user measurement equipment unrelated QKD system and method based on a GHZ entangled state. The multi-user measurement equipment unrelated QKD system comprises N + 1 senders and N measurement parties, wherein the first sender, the second sender,..., and the Nth sender are connected with each other through a classical channel, the Nth sender and the Nth measurer are connected one by one through quantum channels, and the (N + 1)th sender is connected with the first measurer, the second measurer,..., and the Nth measurer through quantum channels. And the first sender, the second sender,..., and the Nth sender send the single photon polarization state, and the (N + 1)th sender sends the GHZ entangled state. Particles prepared by the first, second,..., Nth and (N +1)th sending parties interfere with each other in the first, second,..., Nth measuring parties, Bell state measurement is carried out, and a code value is formed. According to the invention, the communication distance is greatly increased, the attack on the measurement equipment can be resisted, and the first, second,..., and Nth measurement parties in the invention can be non-trusted parties.

Description

technical field [0001] The invention relates to the field of quantum communication of vehicle information, in particular to a multi-user measuring equipment-independent QKD system and method based on GHZ entanglement state. Background technique [0002] Quantum key distribution technology (QKD) is an important technology based on quantum mechanics and information theory used in quantum cryptographic communication (Quantum Cryptography). In the presence of an eavesdropper (Eve), the two communicating parties (Alice, Bob) conduct secure communication on the basis of the unconditional security theory of quantum communication. In 1984, Bennett et al. proposed the first QKD protocol - BB84 protocol. However, due to the differences between the actual system and the theory, there are various loopholes in the actual system, so Eve can attack the communication process through these loopholes. In response to various problems in the system, many protocols have been proposed one after...

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Problems solved by technology

[0011] In 2013, Xu et al. conducted research on the MDI-QKD protocol of entangled states, which increased the loss tolerance of quantum secure communication by adding quantum relay terminals, that is, increased the distance of quantum secure communication, but the sender of the entangled state What is sent is the EPR entangled state, and the research only focuses on the quantum key distribution of two parties, and does not consider the quantum secret communication of multiple parties

[0012] In the patent 201710034284, the QKD protocol based on the GHZ state is described. It hopes that the third party Charlie will send the GHZ entangled state for key distribution, and state that the third party is untrustworthy, but obviously distributes the entangled state Charlie is not likely to be an untrusted end

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