Why this tool is useful
Use Beaufort to compare a reciprocal polyalphabetic cipher with Vigenère while keeping the calculation visible and reproducible.
Text & List Tools · runs locally
Beaufort Cipher Tool
Apply the reciprocal Beaufort tableau formula to Latin text with a repeated alphabetic key and preserved punctuation.
Ready. Your working data stays in this browser.
How it works
For each Latin letter the browser calculates key minus plaintext modulo 26; the same operation decrypts the result, so no direction toggle is needed.
Practical example
Key FORTIFICATION transforms DEFENDTHEEASTWALLOFTHECASTLE into CKMPVCPVWPIWUJOGIUAPVWRIWUUK.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.