Classical Cryptography

A selection of classical cryptographic techniques for use with the Latin alphabet.

Cipher List

• Polybius Square
  • Bifid
  • Trifid
  • Nihlist
• Caesar
• Playfair

Example Usage

Perform a ROT13 cipher shift on a simple plaintext:

python3 crypto.py "HELLO WORLD" -c caesar -e -k 13

Decipher polybius coordinate numbers using a standard polybius square:

python3 crypto.py 23153131345234423114 -c polybius -d

Encrypt a plaintext using the key "HELLO" and a polybius square shifted with the keyword "WORLD":

python3 crypto.py HELLOWORLD -c nihlist -k HELLO -s WORLD