We return to the series on columnar transposition ciphers to discuss permutations, how CTCs can be thought of as permutations, and some questions that this connection opens up.

Today’s Math Monday begins a multi-part series on the columnar transposition cipher. Today’s Math Monday begins a multi-part series on the columnar transposition cipher. Skip to content.

To write a substitution cipher, replace the plaintext with other symbols without changing the sequence. Plaintext: The dog is under the desk. Substitution cipher: 20 8 5 4 15 7 9 19 21 14 4 5 18 ...

Double Transposition Cipher Solution Back to Double Transposition Hint Normally the keys would be numbered like this: 11 1 1 1 81520194673 327811504692 MAHATUNDILA CULLATINDILA However, Agent ...