1. An apparatus, comprising: a processor; a memory; and an interface to connect the processor, the memory, and a set of logics, the set of logics comprising: an establishment logic configured to instantiate a first one-to-many de-duplication data structure that is configured to receive a key value and to return one or more items that facilitate making one or more of, a decision concerning whether a similarity determination is to be made, and a similarity determination for a block of data to be de-duplicated; and a manipulation logic configured to selectively update the one-to-many de-duplication data structure by performing one or more of, adding an item that facilitates making the similarity determination, and deleting an item that facilitates making the similarity determination.