On the Subject of the Columnar CM

The numbers shown on screen 1 will be referred to as the Columnar Key.

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

Encrypt Instructions

  • Write the encrypted word underneath the Columnar Key so that it fits in the columns of the key.
  • Rearrange the columns so that the numbers are in ascending order.
  • Read the letters top to bottom, left to right to get a decrypted word.

Decrypt Instructions

  • Put X dashes under the Columnar Key so that it fits in the columns of the key. X is equal to the encrypted word's length.
  • In ascending order, take the encrypted word and replace all the dashes under the Columnar Key with the letters.
  • Read the letters in reading order to get a decrypted word.

Example 1

Encrypted Word: TETRHEA
Columnar Key: 43152
Using Encrypt Rules

43152
TETRH
EA
12345
THETR
AE

Decrypted Word: THEATER

Example 2

Encrypted Word: OTNUAMNI
Columnar Key: 312
Using Decrypt Rules

312
---
---
--
312
-O-
-T-
-N
312
-OU
-TA
-N
312
MOU
NTA
IN

OTNUAMNI → MOUNTAIN