Computerized cryptanalysis has obviously made formerly "secure" hand ciphers like Playfair, Four Square, and the Hill Cipher obsolete because they can be defeated in seconds. But is there a hand cipher where a modern computer attack does not have an advantage over a cryptanalysis done by hand? There are certainly tasks that are more quickly done by humans, rather than computers. I'm wondering if there is a hand cipher that takes advantage of this.
One time pad is definitely both easy to do and has perfect secrecy, but key management is a pain and can compromise security. Basically a Vigenère cipher with a key as long as the the message should be secure, because different keys can create ALL possible messages with equal probabilities.
Again, it's a one time pad, so no KPA, CPA, or CCA security. Actually I don't think any pen & paper cipher system has such security.
The solitaire cipher is pretty good. The number of ways to shuffle the card pack is 2.3 e71. This is a huge number of possibilities that even a computer couldn't check through...