Four-particle GHZ state-based two-party quantum key agreement protocol

Abstract

The invention discloses a four-particle GHZ state-based two-party quantum key agreement protocol. The protocol includes the following steps that: step 1, Alice and Bob randomly generate respective classic keys and negotiate on functions; step 2, Alice selects n four-particle GHZ combination and separation sequences, and randomly inserts decoy photons into three sequences and transmits the new sequences to Bob; step 3, Bob measures the decoy photons, and Alice calculates an error rate; step 4, Alice executes CNOT operation on every three corresponding particles with the same serial numbers in the sequences by twice; step 5, Alice executes unitary transformation so as to obtain new sequences, and selects out the decoy photons and inserts the decoy photons into the sequences and transmits the sequences to Bob; step 6, Bob measures the decoy photons; Alice compares measurement results and calculates an error rate, and step 7 is executed if the error rate is low, otherwise, the method returns to step 2; step 7, Alice generates a shared key; and step 8, Bob generates a shared key. With the four-particle GHZ state two-party quantum key agreement protocol of the invention adopted, existing participant attacks and the external attacks can be resisted. The quantum bit efficiency of the protocol is much higher than that of an existing protocol.

Description

technical field

[0001] The invention belongs to the field of quantum communication, and in particular relates to a quantum key agreement (Quantum key agreement) protocol, in particular to a two-party quantum key agreement agreement based on a four-particle GHZ state. Background technique

[0002] Quantum cryptography is a new technology for communication and network security, and its security is guaranteed by the basic principles of quantum mechanics. Unlike traditional cryptography, which is mostly computationally secure, quantum cryptography can achieve unconditional security, which has attracted a lot of attention. The quantum key agreement (QKA) protocol is a new important branch of quantum cryptography, which allows participants to negotiate a classical shared secret key through an open quantum channel, and the contribution of each participant is the same, any participant None or a subset of participants can independently determine the shared secret. Using the shared ...

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