An authenticable and machine readable coating for pills, tablets and other ingestible materials is provided. The disclosure also relates to methods of authenticating the same. The coatings are formed from a lattice of particles stacked to cause selective diffraction such that each pill or tablet has an optical signature. The signature associated with each coating can be read and authenticated. In one embodiment, the particles are substantially spherical and self-organized. In one embodiment, generally recognized as safe (GRAS) materials are used to form the particles.

Methods for measuring and verifying drug portions while avoiding the need to teach verification devices is provided. Characteristic key data of a drug type are compiled with a calibrated camera of a measuring device, stored in a storage device, and retrieved from or transmitted to a verification device. Individual key data for a drug portion to be verified are compiled using a calibrated camera of the verification device and compared with the characteristic key data. A digital image of a drug portion to be verified is generated with a calibrated camera and transferred to a control unit. The control unit determines individual key data for the drug portion to be verified using known calibration parameters of the camera and the digital image, compares the individual key data with characteristic key data of the corresponding drug type and verifies or rejects the drug portion based on the results of the comparison. Systems and computer readable medium are also provided.