For people interested in these kinds of things, there is a very interesting military manual on the internet archives which goes though all the various pre compu

For people interested in these kinds of things, there is a very interesting military manual on the internet archives which goes though all the various pre computer pen and paper ciphers and how to crack them. 1. https://archive.org/details/Fm3440.2BasicCryptAnalysis/mode/1up https://archive.org/details/Fm3440.2BasicCryptAnalysis/mode/...