Abstract: In some embodiments, an apparatus includes a tag that may include an encapsulant and a plurality of three-dimensional objects randomly oriented within the encapsulant. Each three-dimensional object may include a plurality of characteristics defining at least one statistically unique signature. At least one of the characteristics may be dependent on the orientation of the object. In some instances, the plurality of three-dimensional objects may also be randomly distributed within the encapsulant, and at least one of the characteristics defining at least one statistically unique signature may be dependent on the distribution of the objects.