On the Subject of the Tridigital CM

A machine that knows no bounds when it comes to ciphers.

Create a key using the keyword on screen 1 and the Boolean Expression on screen A. Then split the key into 3 rows of 9 letters with the last row only being 8 letters. This will be referred to as the Tridigital Key.

Turn each letter of the encrypted word into its alphabetic position (A1Z26)). Subtract 9 from each number until it is within the range of 1-9.

Take the digit string from screen 2 and place it above the digit string you created with the encrypted word.

Read each number pair, top to bottom, left to right. These will be your row/col pairs.

For each row/col pair, use the intersection in the Tridigital Key to get a decrypted letter. Do this for all row/col pairs to get a decrypted word.

Example

Encrypted Word: DXSKMTTK
Key: DEFCTABGHIJKLMNOPQRSUVWXYZ
Digit String: 11312133

1 + D → 14 → C
1 + X → 16 → A
3 + S → 31 → R
1 + K → 12 → E
2 + M → 24 → L
1 + T → 12 → E
3 + T → 32 → S
3 + K → 32 → S

Decrypted Word: CARELESS