On Sunday, August 1, 2021, 04:37:58 PM PDT, Sampo Syreeni <de...@iki.fi> wrote: >Many years ago I posted an idea of mine about cryptographic physical watermarking of things, such as paper money, or maybe missiles. Whatnot.
>The idea was that you'd do some chaotic physical process in order to lay down a physical watermark, then image it, and finally digitally sign what was seen via asymmmetric cryptography. I imagined you'd then print the signature "on the bill" as a 2D barcode, to be verified. But I never worked out how you would deal with the inevitable "broken bill". I thought it'd take some kind of high end error correcting code. [snip] >Any problems with my idea? I'd like to hear, especially since it has been a couple of decades coming. -- Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front +358-40-3751464, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 About 40 years ago, I bought the latest Pat Benatar album (yes, vinyl!) from Tower Records in Beaverton Oregon. Get Nervous | | | | | | | | | | | Get Nervous Get Nervous is the fourth studio album by American rock singer Pat Benatar, released in October 1982. It debuted... | | | Inside the plastic shrinkwrap, there was a white post-card-sized white card, printed with a return address, and an area on the card with a horizontal- and vertical- marked target, about an inch square. I believe it was an anti-bootleg device. I concluded that the cards were printed and given an ID number, and then scanned, perhaps on the surface or perhaps transmission through the card. That information was probably stored. People were to fill out the cards and return them to the manufacturer to re-scan. I think the intent was that it would be impossible to fake the card, because the information was embedded in the fibers in the structure of the card itself. If anybody tried to bootleg the album, they could not re-create the internal pattern of the paper. Jim Bell
