Back to Tools

Beaufort Cipher

Polyalphabetic substitution cipher using key letter minus plaintext letter.

The Beaufort cipher, created by Sir Francis Beaufort, is a polyalphabetic substitution cipher similar to the Vigenere cipher. Instead of adding letter values, it calculates each cipher letter by taking the key letter minus the plaintext letter. This tool supports both standard and autokey Beaufort modes.

Enter a keyword to derive a custom alphabet, or leave blank for A-Z.

Tabula Recta

The cipher uses this table for encipherment. Updates when alphabet changes.