On the Subject of the Nicodemus CM

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

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 keyword on screen 1 so that it fits in the columns of the keyword in reading order.
  • For each column, move each letter in the Nth column forward in the alphabet equal to the alphabetic position of the Nth letter of the keyword (A1Z26).
  • Read each letter in alphabetical order according to the keyword. In the case of duplicate letters, read them from left to right, top to bottom for the current duplicate letter.
  • The resulting letters should form a decrypted word.

Decrypt Instructions

  • Write X dashes underneath the keyword on screen 1 so that it fits in the columns of the keyword in reading order. X is equal to the length of the encrypted word.
  • Place each letter of the encrypted word in alphabetical order via the keyword, replacing each dash underneath the letter. In the case of duplicate letters, place them from left to right, top to bottom for the current duplicate letter, until each of the dashes underneath the duplicate letters have been replaced.
  • For each column, move each letter in the Nth column backward in the alphabet equal to the alphabetic position of the Nth letter of the keyword (A1Z26).
  • Read the letters in reading order to get a decrypted word.

Example 1

Encrypted Word: NDWIWXFO
Keyword: UPLIFT
Using Encrypt Rules

UPLIFT
NDWIWX
FO
UPLIFT
ITIRCR
AE

Decrypted Word: CRITERIA

Example 2

Encrypted Word: CMTXVXD
Keyword: POLIO
Using Decrypt Rules

POLIO
XTMCX
DV
POLIO
HEATI
NG

Decrypted Word: HEATING

You can use this table as a way to get your decrypted letters. To do so, follow the instructions below:

  • Use the keyword's letter as the row.
  • If you are adding, use the encrypted word's letter as the column. The intersection of the 2 will be your decrypted letter.
  • If you are subtracting, find the encrypted word's letter within the row. The column that the letter is in becomes your decrypted letter.
ABCDEFGHIJKLMNOPQRSTUVWXYZ
ABCDEFGHIJKLMNOPQRSTUVWXYZA
BCDEFGHIJKLMNOPQRSTUVWXYZAB
CDEFGHIJKLMNOPQRSTUVWXYZABC
DEFGHIJKLMNOPQRSTUVWXYZABCD
EFGHIJKLMNOPQRSTUVWXYZABCDE
FGHIJKLMNOPQRSTUVWXYZABCDEF
GHIJKLMNOPQRSTUVWXYZABCDEFG
HIJKLMNOPQRSTUVWXYZABCDEFGH
IJKLMNOPQRSTUVWXYZABCDEFGHI
JKLMNOPQRSTUVWXYZABCDEFGHIJ
KLMNOPQRSTUVWXYZABCDEFGHIJK
LMNOPQRSTUVWXYZABCDEFGHIJKL
MNOPQRSTUVWXYZABCDEFGHIJKLM
NOPQRSTUVWXYZABCDEFGHIJKLMN
OPQRSTUVWXYZABCDEFGHIJKLMNO
PQRSTUVWXYZABCDEFGHIJKLMNOP
QRSTUVWXYZABCDEFGHIJKLMNOPQ
RSTUVWXYZABCDEFGHIJKLMNOPQR
STUVWXYZABCDEFGHIJKLMNOPQRS
TUVWXYZABCDEFGHIJKLMNOPQRST
UVWXYZABCDEFGHIJKLMNOPQRSTU
VWXYZABCDEFGHIJKLMNOPQRSTUV
WXYZABCDEFGHIJKLMNOPQRSTUVW
XYZABCDEFGHIJKLMNOPQRSTUVWX
YZABCDEFGHIJKLMNOPQRSTUVWXY
ZABCDEFGHIJKLMNOPQRSTUVWXYZ