On the Subject of the Notre-Dame CM
A machine that knows no bounds when it comes to ciphers.
From the Notre-Dame Cipher module by Konoko.
This cipher uses 2 pages.
Create a key using the keyword on screen 1 and the Boolean Expression on screen A. Make sure to replace any Qs with Zs. Rearrange the key into a 5×5 matrix. Keep a copy of this matrix for the last step.
Scramble the starting matrix to get the ending matrix by following the instructions below:
- Locate the cell on the Nth number screen on page 1 using the letter for the column and the number for the row.
- Locate the 3 other cells using 90° rotations along the center of the matrix.
- If the character on the Nth letter screen on page 1 is a '>', swap the 4 cells clockwise.
Otherwise, swap the 4 cells counter-clockwise.
- The number on the Nth number screen on page 2 will be referred to as the Key Number.
- The 1st number of the Key Number points to the starting column and the 2nd number the ending column.
- Take the X letters from the top of the starting column, where X is the 3rd number of the Key Number, and stack them one by one on top of the ending column.
- Also take the X letters from the bottom of the ending column and stack them one by one at the bottom of the starting column.
- The 1st number on the Nth letter screen on page 2 will be used as the column, while the 2nd number will be used as the row.
- WITHOUT MOVING the letter in the intersection of these two, swap their content while keeping the reading order (top goes to left, right goes to bottom, and vice-versa).