On the Subject of the Gracie 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. Split the key into 2 equal halves and place the 2nd half underneath the 1st half. This will be referred to as the Gracie Key.

Split the encrypted word into pairs of letters. If there is an odd amount of letters, leave the last letter as the odd letter. Depending on which instruction is required, apply it to each pair of letters.

If the Submit Button is white, follow the instructions under Encrypt Instructions. Otherwise follow the instructions under Decrypt Instructions.

Encrypt Instructions

  • If the 2 letters are the same, replace each letter with the letter that is in the opposite column and opposite row of the Gracie Key.
  • Otherwise, if the letters appear on the same row of the Gracie Key, replace them with the letters that are above/below them.
  • Otherwise, if the letters appear on the same column of the Gracie Key, replace them with the letters immediately to their right, wrapping around when necessary.
  • Otherwise, replace each of them with the letter on the same row but in the column of the other letter in the original pair.

Decrypt Instructions

  • If the 2 letters are the same, replace each letter with the letter that is in the opposite column and opposite row of the Gracie Key.
  • Otherwise, if the letters appear on the same row of the Gracie Key, replace them with the letters that are above/below them.
  • Otherwise, if the letters appear on the same column of the Gracie Key, replace them with the letters immediately to their left, wrapping around when necessary.
  • Otherwise, replace each of them with the letter on the same row but in the column of the other letter in the original pair.

Example 1

Encrypted Word: QSKNJPR
Using Encrypt Rules

BCDFGHIJKMNOQ
RUVWXYZPETALS

QS → BR
KN → EA
JP → KE
Decrypted Word: BREAKER

Example 2

Encrypted Word: LECMJJST
Using Decrypt Rules

WORKABLECDFGH
IJMNPQSTUVXYZ

LE → ST
CM → RU
JJ → GG
ST → LE
Decrypted Word: STRUGGLE