This is a 3D print of a machine that implements an easily broken polyalphabetic substitution cipher.

It has three wheels with different alphabets and a base plate to mount them. The base plate has pins to mount the wheels and indexing dots to set the initial relationship between them. As the wheels turn, the letters indicated by the indexing dots change.

To use the machine, the first thing is to decide on a wheel order and a three letter setting. Place the base plate so the letter Y is readable, install the wheels in the machine and align the selected letter for that wheel with the corresponding indexing hole on the base plate.

The product picture shows wheels I(AB...) II(AJ...) III(AZ...) installed from left to right with CAT as the three letter setting.

The actual procedure for encrypting the letters is left to the user. One such procedure is to use the left wheel to input the clear text and read the encrypted text on the middle and right wheels alternatively.

For example, using the settings shown in the product picture, to encrypt the word HELLO, rotate the left wheel until the letter H is aligned with the dot and read the letter indicated by the middle wheel (it happens to be H). Rotate the left wheel to the letter E and read the letter on the right wheel (S). Next, rotate the left wheel to the letter L and read the middle and right wheels (X and L). Finally, turn the left wheel to the letter O and read the result in the middle wheel (W). Thus, the word HELLO is encrypted to HSXLW.

To reverse the procedure, first turn the middle wheel to the letter H and read the result in the left wheel (H). Next turn the right wheel to the letter S and read the result in the left wheel (E). Continue alternating between the middle and right wheels until the whole text is decrypted.

Another procedure is to rotate the left wheel to the first letter (H) and read the result in the middle wheel (H). Then rotate the middle wheel to the letter E and read the result in the right wheel (Z). Next, rotate the right wheel to the letter L and read the result in the left wheel (L). Then use the left wheel to indicate the input character (L) and read the result in the middle wheel (X). Finally, turn the middle wheel to O and read the character in the right wheel (O).

Thus, HELLO is encrypted to HZLXO using this method. Not an impressive result, another starting letter combination might be better.

To recover the initial text, start by turning the middle wheel to the first encrypted letter and recover the clear text in the left wheel. Next, turn the right wheel and recover the clear text in the middle wheel. Continue selecting the input wheel in a clockwise motion around the base plate and read the decrypted result in the previous wheel.

Other encryption/decryption procedures can be created by the user.

Two machine base plates can be glued side to side to a bigger base and a larger six wheel machine can be created!!

As you can see, depending on the initial settings, a letter might encode to itself on two or all wheels. This cipher is trivial to break and is best suited for educational or amusement purposes such as teaching children about basic encryption or for use in escape rooms.

This product shows the normal texture marks of any 3D printed object. The letter definition is very sharp. It has been printed on white PLA with a high percentage of infill (40%) and it feels very solid. The wheels spin freely for a couple of seconds on a good flick of the finger, the PLA on PLA seems to be self lubricating.

Shipping is $3.34 within the USA, $13.30 to the rest of the world.

To save on shipping, two other products can be added, a very loud Aztek Death Whistle (google it) (38mm wide, 45mm tall) and a customized name plate with the text of your choice. The listing shows a plaque that is 94x30mm, text is 10mm peak to peak, the letter O is 6mm tall, mounting holes are 3mm diameter

Technical Data:

Wheel 1 (alphabet in order): ABCDEFGHIJKLMNOPQRSTUVWXYZ

Wheel 2 (AJ..) AJSBKTCLUDMVENWFOXGPYHQZIR

Wheel 3 (AZ..) AZBYCXDWEVFUGTHSIRJQKPLOMN

Wheel Dimensions: 54mm (2 1/8") diameter 6.5mm (1/4") thick

Base Plate Dimensions: 94.5mm (3. 3/4") wide 79mm (3 1/8") long 9.5mm (3/8") thick (includes posts)

With the wheels installed, the machine is 112.5mm (4 7/16" wide)

Licenses:

These designs have been placed in the public domain by their original creators, allowing anybody to download, print and ethically sell these. The enigma machine takes a total of about 8 hours to print. The death whistle, about 1:40.

Zahnrad Enigma für BrainBox oder Escape-Room (Gear Enigma for BrainBox or Escape Room by erhome00

Death Whistle By Jinkai

Both designs are unmodified and licensed under the Creative Commons - Attribution license. Commercial Use is allowed.