A hierarchical row decoder is for a phase-change memory device provided with an array of memory cells organized according to a plurality of array wordlines and array bitlines. Embodiments apply one or more self-keying techniques to a content dataset to generate an anticipatory dataset, such that the anticipatory dataset cannot be used to reconstruct the content dataset without a keying dataset that also can only be generated using the content dataset. Each first power signal is based on estimating over a first time period the power of one of the frequency band signals. The cam plate is coupled to the drive shaft for rotation therewith.