| 摘要 |
The document securization method comprises: a step of printing a distribution of dots on said document, said printing, as a 5 result of unanticipated unknowns in printing, causing an unpredictable variation, dot by dot, of at least one geometric characteristic of the printed dots; and prior to said print step, a step of generating said distribution of dots so that dots of said distribution have at least one geometric characteristic that varies among dots, the geometric amplitude of the generated variation having the order of magnitude 10 of said unpredictable variation. In embodiments, during the generation step, in said dot distribution: at least half the dots of said distribution are not laterally juxtaposed to four other dots of said dot distribution; and at least one dimension of at least one part of the dots of said dot distribution is 15 of the same order of magnitude as the average for the absolute value of said unpredictable variation. Receiving a cryptographic key 701 Generating random binary values 702 + 703 Assembling binary values into a pattern + 720 Receiving the surface area available Generating patten images with different resolutions 721 Printing the various images 722 Capturing images of the printed patterns Calculating imprints (see steps 711 to 715) 724 + 725 Calculating similarity scores Selecting a resolution 726 + 727 Printing the object with the identifier pattem Determining the position of the identifier pattern + 712 Extracting values of dots of the identifier pattem + 713 Calculating a discrete cosine transform Selecting coefficients of the transform - 731 Determining extreme values Determining the number of bits required - 733 Normalizing the coefficients - 734 Multiplying by the number of possible values Sequencing coefficients into a vector Figure 28A |
