A method begins with a computing device of a dispersed storage network (DSN) determining that an encoded data slice of a set of encoded data slices requires rebuilding and sending partial rebuild requests to storage units of the DSN. The method continues with one of the storage units generating a partial rebuilt slice based one or more encoded data slices of the set of encoded data slices stored by the one of the storage units and securing the partial rebuilt slice using a shared secret scheme that is shared among the storage units to produce a secured partial rebuilt slice. The method continues with the computing device receiving a set of secured partial rebuilt slices from the storage units, recovering a set of partial rebuilt slices from the set of secured partial rebuilt slices, and rebuilding the encoded data slice from the set of partial rebuilt slices.