Multi-party Quantum Key Agreement Protocol Based on Ring Structure

Abstract

The invention discloses a ring structured based multi-party quantum key agreement (MQKA) protocol, which is characterized in that each participant prepares a single photon sequence and sends the prepared single photon sequence to the next participant; each participant encodes through a unitary operation so as to generate a new sequence and sends the new sequence to the next participant until each participant receives the single photon sequence which is initially prepared by himself; each participant Pi (i=1, 2,..., n) counteracts control operations performed by the other (n-1) participants on each photon in a sequence Si (i+1)..., (i-1) through executing the unitary operation; the photons, on which the counteracting operation is performed, are measured by using a corresponding measuring basis, then a bit string is extracted from a measuring result, finally eavesdropping detection is performed by using the bit string, and a final key is inferred. The ring structure based MQKA protocol provided by the invention can ensure the key security and the fairness simultaneously. Only one time of eavesdropping is required to be performed in the whole protocol process, so that the quantum bit efficiency of the kind of protocols is significantly improved.

Description

technical field [0001] The invention relates to a multi-party quantum key agreement protocol based on a ring structure. Background technique [0002] There are usually two types of cryptographic basic protocols for establishing random keys between communicating parties through insecure channels, one is Key Distribution (KD), and the other is Key Agreement (Key Agreement, KA). In KD, usually a protocol participant generates a set of random keys, and then sends it to other participants through corresponding methods. In KA, the participants of the protocol need to fairly establish a set of random keys based on mutual information interaction, that is, each participant should contribute his part of the influence to the final key established. In other words, the final key established in the KA protocol cannot be determined by any non-trivial subset of protocol participants. Therefore, KA not only needs to ensure the security of the key, but also needs to ensure the fairness of t...

AI Technical Summary

Problems solved by technology

In 2013, Sun et al. proposed an efficient MQKA protocol based on a ring structure using single photon states, but this protocol also proved to be unfair

However, the existing ring-based MQKA protocols generally have the following problems: on the one hand, most of the existing ring-type MQKA protocols cannot resist collusion attacks from participants, that is, there is a fairness problem; on the other hand, Some MQKA protocols that can guarantee fairness need to perform eavesdropping detection after each transmission of the quantum information carrier sequence, resulting in a greatly reduced qubit efficiency of the protocol and losing the advantage of high qubit efficiency of the ring structure MQKA protocol

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