Polybius Square Cipher

The Polybius Square is essentially identical to the simple substitution cipher, except that each plaintext character is enciphered as 2 ciphertext characters. You can customize the alphabet with a keyword or phrase. Also, the KEY must be 5 characters long and not repeat in order for this cipher to work.


Enter a keyword, phrase, or alphabet and the rest will be calculated for you.

Ciphertext Key: