1. A drug unit authentication system, comprising a plurality of drug units, each drug unit containing a drug common to the plurality of drug units, and each drug unit having a deposited random integrated optically identifiable marking on a surface of or within a drug unit, wherein the marking of each drug unit in the plurality of drug units has a size, shape, location or distribution unique and differentiatable from the markings of all other of the drug units in the plurality of drug units, wherein each drug unit in the plurality of drug units has a secondary product identifier common to the plurality of the drug units and related to the common drug of the plurality of drug units, wherein the marking is configured for use in a comparison of a selected one of the drug units and drug unit marking data associated with the selected one of the drug units and being related to the markings and the second product identifier for the selected one of the drug units.