Verifiable object having incremental key.

摘要

An object verification system generates an incremental verification key which can be carried on the object co-extensive with the region of the associated randomly varying characteristic. The incremental key can be formed by measuring values of the characteristic and comparing selected pairs of values. The algebraic sign of the comparison can be used as an indicium for creating a verification key distributable across the region of the object. Alternately, the magnitude of the difference between the selected pairs of values can be also be included in some or all of the indicia.