The problem of the incorporation of pattern features with unusual distributions is well known within Pattern Recognition systems even if not easily addressed. The problem is more acute when features are derived from characteristics of given integrated electronic circuits. The current paper introduces novel efficient techniques for normalising sets of features which are highly multi-modal in nature, so as to allow them to be incorporated within a single encryption key generation system based primarily on measured hardware characteristics.The utility of the proposed system lies in the observation that the need for data sent to and from remote network nodes to be secure and verified is substantial. Security can be improved by using encryption techniques based on keys, which are based on unique properties of the individual nodes within the network. This will serve both to minimize the need for key storage and sharing as well as to validate the initiator node of a message.