2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/144699We propose a quantum key distribution (QKD) protocol that enables three parties agree at once on a shared common random bit string in presence of an eavesdropper without use of entanglement. We prove its unconditional security and analyze the key rate.8 pages, no figureQuantum Physicstext