Trifid Cipher
Encrypt and decrypt with a keyed 3 × 3 × 3 cube, adjustable period, and an interactive coordinate walkthrough.
Input
Output
The 3 × 3 × 3 Trifid Cube
Each symbol occupies a unique layer · row · column address. Select a symbol to inspect its coordinates; tinted cells also appear in the currently selected working block.
Step-by-Step Fractionation
See exactly how a block is transformed.
Enter some text or choose Load Example to see the cube and coordinate transposition in action.
Cipher Properties
Inventor Félix Delastelle
Family Fractionating cipher
Alphabet 27 symbols
Grid 3 × 3 × 3
Period 5
Mode Encrypt
Classical cipher, not modern security. Trifid combines substitution, fractionation and transposition to conceal simple letter patterns, but it is not suitable for protecting confidential information. For interoperability, both parties need exactly the same 27-symbol cube alphabet and period.
Using This Tool: Guide & Notes Show guide
Trifid turns A–Z and the dot into layer, row and column coordinates, mixes those coordinates within each period block, and converts them back into symbols.
How to use it
- Choose Encrypt or Decrypt, then type or paste a message. The result updates automatically; Update result also focuses the output.
- Keep the standard cube, enter a complete cube alphabet, or use the keyword builder followed by Use keyword. Both parties must use exactly the same alphabet order and period.
- Load example sets the keyword FELIX MARIE DELASTELLE and period 5. AIDE-TOI, LE CIEL T'AIDERA produces FMJFV OISSU FTFPU FEQQC.
- Select a cube cell or input symbol to inspect its layer–row–column coordinates. Use the block arrows to follow each block through the walkthrough.
- Copy the result, or choose Swap input/output to move it into the input and reverse the direction.
Options and settings
- Cube alphabet must contain every letter A–Z and exactly one dot, in any order. It fills each layer row by row; J remains a separate letter.
- Keyword builder uses A–Z only, removes repeated letters, then appends unused letters and the dot. Example cube applies the worked-example keyword; Random cube shuffles all 27 symbols.
- Fractionation period accepts whole numbers from 0 to 1000. A positive value mixes that many symbols per block; 0 mixes the whole message. A shorter final block is processed without padding. Period 1 leaves each symbol unchanged.
- Group ciphertext formats encrypted output in groups of 2–12 symbols. This display setting does not change the fractionation period. Grouping disables case and separator preservation.
- With grouping off, Preserve case follows the case of the current input. Keep spaces & other punctuation copies unsupported characters in their current positions; neither setting can recover formatting previously removed.
Notes
- The dot is an encrypted 27th symbol, not ordinary punctuation. Digits, spaces, accented letters and other unsupported characters do not advance the cipher; they are discarded unless separator preservation is enabled.
- All processing happens locally in your browser. Input is limited to 50,000 characters; detailed walkthroughs are displayed for blocks of up to 40 symbols to keep the page responsive.
- Trifid is a historical cipher for learning and puzzles, not modern protection for confidential information. The cube alphabet and period are both needed to reverse a message.
Related Article
Trifid Cipher: A Secret Hidden in Three Dimensions
How Félix Delastelle turned letters into three coordinates, mixed their fragments, and made a simple alphabet considerably harder to recognise.