Tree Quantum Key Agreement Protocol for Secure Multiparty Communication

The paper introduces a tree multiparty quantum key agreement protocol for secure communication between multiple participants, specifically tailored for tree topologies. Based on the BB84 protocol, the proposed solution employs hierarchical tree structures and XOR operations to facilitate efficient and secure key generation. Key elements are exchanged among participants in an equitable manner, ensuring that each participant contributes equally to the generation of the shared key. The protocol demonstrates robust security, effectively defending against both external and internal attacks, and achieves a quantum efficiency of ½(N–1), where N is the number of participants. Additionally, the protocol is readily implementable with current quantum technologies, utilizing single-photon transmission to facilitate secure key distribution.