  Maximally entangled states are a key resource in many quantum communication
and computation tasks, and their certification is a crucial element to
guarantee the desired functionality. We introduce collective strategies for the
efficient, local verification of ensembles of Bell pairs that make use of an
initial information and noise transfer to few copies prior to their
measurement. In this way the number of entangled pairs that need to be measured
and hence destroyed is significantly reduced as compared to previous, even
optimal, approaches that operate on individual copies. Moreover the remaining
states are directly certified. We show that our tools can be extended to other
problems and larger classes of multipartite states.
