Methods and a system for verifying the authenticity of a mark

A method for establishing a signature for a printed mark, the method comprising:

• printing a mark, wherein the printed mark includes imperfections resulting from a printing process that printed the mark;
• capturing an image of the printed mark;
• forming a genuine mark signature based on the imperfections by carrying out steps comprising
• extracting one or more optical or physical characteristics of the printed mark at a plurality of locations on the printed mark;
• trimming the optical or physical characteristics by removing one or more dominant optical or physical characteristics;
• encoding the trimmed optical or physical characteristics of the printed mark into a verification metric data set;
• storing the genuine mark signature in a database;
• and
• applying the printed mark to an item.

A computer system comprising a processor that carries out actions comprising:

• receiving an image of a candidate mark from an image acquisition device;
• using the image to measure one or more characteristics at a plurality of locations on the candidate mark, resulting in a first set of metrics;
• removing a highest metric from the first set of metrics, resulting in a trimmed first set of metrics;
• retrieving, from a computer-readable memory, a second set of metrics that represents one or more characteristics measured at a plurality of locations on an original mark;
• removing, from the second set of metrics, a metric corresponding to the metric removed from the first set of metrics, resulting in a trimmed second set of metrics;
• comparing the trimmed first set of metrics with the trimmed second set of metrics;
• determining whether the candidate mark can be verified as genuine based on the comparison;
• if, based on the comparison, it is determined that the mark cannot be verified to be genuine, carrying out further actions comprising:
• removing a next highest metric from the trimmed first set of metrics, resulting in a further trimmed first set of metrics;
• removing, from the trimmed second set of metrics, a metric corresponding to the metric removed from the trimmed first set of metrics, resulting in a further trimmed second set of metrics;
• comparing the further trimmed first set of metrics with the further trimmed second set of metrics;
• determining whether the mark can be verified to be genuine based on the comparison of the further trimmed first set of metrics and the further trimmed second set of metrics;
• and
• repeating the removing, comparing, and determining steps for successively further trimmed sets of metrics until the metrics remaining in the trimmed first set of metrics for the candidate mark is less than a predetermined threshold amount.