Recent research highlights the use of letterlocking techniques
nytimes.com
5 threads
Is it correct that letterlocking is a technique that requires quantum technology to replicate in the digital realm? Strong crypto only works if you know with certainty your private key is still private.
video of how it's done: https://www.youtube.com/watch?v=dzPE1MCgXxo
This is the best resource IMO. I've sent a few letters using these techniques for fun. :)
It's just a paywalled article on letter locking.
paywall :(
Was wondering WHY one’s most important secrets would need to be shared.