Are there any paper/human executed crypto systems that have reasonable strength? I am aware of a few candidates so far
- Solitare from Cryptonomicon https://en.wikipedia.org/wiki/Solitaire_(cipher) (54! unique keys)
- Off the grid https://www.grc.com/offthegrid.htm (ridiculous amount of entropy, but having plaintext + ciphertext leaks information about the key) (technically seems more like a hash than encryption, because it doesn't seem reversible with the given method, but the grid could probably be used for some encryption method)
- http://www.ciphergoth.org/crypto/mirdek/
- One time pads (although answers I'm looking for are more like 1-3))
