2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/131599A method for producing an upper bound for all multipartite purification protocols is devised, based on knowing the optimal protocol for purifying bipartite states. When applied to a range of noise models, both local and correlated, the optimality of certain protocols can be demonstrated for a variety of graph and valence bond states.15 pages, 16 figures. v3: published versionQuantum Physicstext