Multiparty-to-multiparty mediated quantum secret sharing protocol in a restricted quantum environment

This study proposes the first multiparty-to-multiparty mediated quantum secret sharing (M2M-MQSS) protocol within a restricted quantum environment. Unlike existing fully quantum secret sharing (QSS) protocols, this protocol allows protocol participants with limited quantum capabilities—including (1) measuring a single qubit in the Z-basis and (2) performing a single-qubit unitary operation, Hadamard operation—to participate, significantly reducing implementation costs. By employing one-way qubit transmission, the proposed MMQSS protocol not only simplifies the quantum communication process but also effectively defends against quantum Trojan horse attacks. The correctness and security analyses demonstrate that the proposed M2M-MQSS protocol is robust against various well-known attack strategies. Simulation experiments confirm the feasibility of the protocol for various numbers of participants. It maintains high levels of efficiency and security even as the number of participants increases. Moreover, compared with existing protocols, the proposed M2M-MQSS protocol lowers the barrier to practical quantum communication deployment by reducing the quantum resources required for protocol participants.