https://www.cs.columbia.edu/2018/fontcode-hiding-information-in-plain-text-unobtrusively-and-across-file-types/
https://arxiv.org/abs/1707.09418
http://www.dailymail.co.uk/sciencetech/article-5719383/Can-spot-hidden-message-Researchers-reveal-method-encrypt-text-plain-sight.html
Researchers at Columbia University have come up with something truly extraordinary, which is changes to fonts so subtle that it takes a computer to distinguish those changes and decode them.
This can be used for:
- Secret messages (of course)
- Encrypted messages – you can use a table provided by a key, and only those with the keyfile can decypher the text
- Replacing QR codes – show the mobile app a poster with plaintext and it’ll come back with a link to “learn more”
- Digital watermarking, as the stenographic data can be a document checksum
- (and more)
Since our printers are so high-res nowadays, it will survive printing, scanning and other digital/analog permutations in both directions.
I’m very impressed that they didn’t release this straight to the military or otherwise focus on profit or business ties, because an app is really required for this one, it would be almost impossible for the public/private sector to reproduce on their own. They went instead to public and as a result have ensured that everyone can benefit from the results of this thought project.
Many US sites are repackaging the research information behind a paywall to try to capitalize on the knowledge even though the inventors made it public… which is pretty messed up. The URL’s above are free (including the whitepaper in .pdf format).