2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/89062A general proof of the security against eavesdropping of a previously introduced protocol for two-party quantum key distribution based on entanglement swapping [Phys. Rev. A {\bf 61}, 052312 (2000)] is provided. In addition, the protocol is extended to permit multiparty quantum key distribution and secret sharing of classical information.REVTeX, 8 pages, 2 figuresQuantum Physicstext