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- What is the most secure hand cipher? 3 answers
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.