As an essential ingredient of quantum networks, quantum conference key agreement (QCKA) provides unconditional secret keys among multiple parties, which enables only legitimate users to decrypt the encrypted message. Recently, some QCKA protocols employing twin-field was proposed to promote transmission distance. These protocols, however, suffer from relatively low conference key rate and short transmission distance over asymmetric channels, which demands a prompt solution in practice. Here, we consider a tripartite QCKA protocol utilizing the idea of sending-or-not-sending twin-field scheme and propose a high-efficiency QCKA over asymmetric channels by removing the symmetry parameters condition. Besides, we provide a composable finite-key analysis with rigorous security proof against general attacks by exploiting the entropic uncertainty relation for multiparty system. Our protocol greatly improves the feasibility to establish conference keys over asymmetric channels.
翻译:作为量子网络的基本要素,量子会议关键协议(QCKA)在多个当事方之间提供了无条件的秘密钥匙,使只有合法用户才能解密加密信息。最近,一些使用双字段的QCKA协议被提出来促进传输距离;然而,这些协议由于会议关键率相对较低,而且对非对称频道的传输距离较短,这就要求在实践中迅速解决问题。在这里,我们认为一个三方QCKA协议利用发送或不发送双字段计划的想法,并通过取消对称参数条件,提出对非对称频道的高效QCKA。此外,我们提供了一个可比较的定键分析,通过利用多党体系的昆虫不确定性关系,对一般性袭击提供严格的安全证据。我们的协议极大地提高了在不对称频道上建立会议钥匙的可行性。