Image Number 4 for United States Patent #7849317.
The present invention uses an element of digital data that is created during digital postage mark (DPM) generation process from the digital image of the destination address block. The digital data is included into recoverable portion of the digital signature and imprinted on a mailpiece. During DPM verification, a representative portion of a destination address block image is retrieved in its original form from the digital signature itself. The retrieved portion of the image then can be compared with the similar digital data obtained from the scanned destination address block obtained during normal mail scanning and processing activities. If the comparison is under a predetermined threshold, then the DPM is declared authentic and the mailpiece can be processed and delivered with confidence. If, on the other hand, the threshold is not met, the DPM is declared a copy or a counterfeit of another DPM and the mailpiece can be subjected to further investigation.