On the Subject of the M-209 CM
A machine that knows no bounds when it comes to ciphers.
This cipher uses 2 pages.
Create an M-209 machine by following the instructions below:
- 1: Write down 16 zeros for row 1, 13 zeros for row 2, 11 zeros for row 3, 9 zeros for row 4, 7 zeros for row 5, and 5 zeros for row 6.
- 2: For each letter on page 1 screen 1, replace the zero with a one with at row 1, at the column equal to the alphabetic position of the letter (A1Z26).
- 3: Repeat step 2 for row 2 using the letters on page 1 screen 2.
- 4: Repeat step 2 for row 3 using the letters on page 1 screen 3.
- 5: Repeat step 2 for row 4 using the letters on page 1 screen 4.
- 6: Repeat step 2 for row 5 using the letters on page 2 screen 1.
- 7: Repeat step 2 for row 6 using the letters on page 2 screen 2.
- 8: For each letter on page 2 screen 3, shift the Nth row to the left, equal to the alphabetic position of the Nth letter, minus 1 (A0Z25).
- 9: Turn each character on pages 1 and 2, screens A–D into a row/col pair using the table below.
- 10: For each row, the offset for the Nth row is equal to the number of N numbers you got from the previous step.
For each letter of the encrypted word, do the following:
- Subtract 27 by the alphabetic position of the Nth letter of the encrypted word (A1Z26).
- For each row of the M-209 machine, if the left most digit is a 1, add the offset of that row to the number.
- If the number is greater than 26, subtract 26 until it is between 1–26.
- Convert the number back to a letter to get your Nth decrypted letter (A1Z26).
- Shift all the rows of the M-209 machine to the left one.
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| 1 | A | B | C | D | E | F |
| 2 | G | H | I | J | K | L |
| 3 | M | N | O | P | Q | R |
| 4 | S | T | U | V | W | X |
| 5 | Y | Z | 0 | 1 | 2 | 3 |
| 6 | 4 | 5 | 6 | 7 | 8 | 9 |