  Quantum secret sharing (QSS) is an essential primitive for the future quantum
internet, which promises secure multiparty communication. However, developing a
large-scale QSS network is a huge challenge due to the channel loss and the
requirement of multiphoton interference or high-fidelity multipartite
entanglement distribution. Here, we propose a three-user QSS protocol without
monitoring signal disturbance, which is capable of ensuring the unconditional
security. The final key rate of our protocol can be demonstrated to break the
Pirandola-Laurenza-Ottaviani-Banchi bound of quantum channel and its simulated
transmission distance can approach over 600 km using current techniques. Our
results pave the way to realizing high-rate and large-scale QSS networks.
