Imagine, if students could start posting free textbook pdf files just by handing out a piece of paper which you could scan, or maybe with a phone one day, and instantly receive the file.
Why not QR code? QR code needs connectivity while this solution would just require you to get your hands on the paper.
Even if a QR code has a maximum size, you could use more than one per page.
https://en.wikipedia.org/wiki/QR_code#Design
I'm sure there are other 2D barcodes that could be used for this application. E.g., Data Matrix (also in the public domain).
>for politics or mass dissemination of paper based digital files for the public to quickly consume
> Imagine, if students could start posting free textbook pdf files just by handing out a piece of paper which you could scan, or maybe with a phone one day, and instantly receive the file.
With both of those, how is this more efficient or easier to pass around than a cheap micro sd card, or just emailing a pdf?
It's also common to print anti-government messages on the money, which might be a great application of paperback/QR - higher density public messages via circulating currency.
Back then (and i think the law is still in place) anything beyond something like a 90-bit key was considered a military weapon, and thus needed relevant export licenses.
But this only applied to working binaries, not the code printed on paper. So what some researchers did was to get the code printed in a book, using a OCR friendly font, and then ship the book to something like Switzerland where it was scanned, compiled, and put online.