Beaufort Cipher
Reciprocal Vigenère variant: encrypt and decrypt are identical.
Reciprocal cipher: Beaufort uses the formula
c = (k − p) mod 26, which is its own inverse. Run the
ciphertext back through with the same keyword to decrypt.
About this tool
Each ciphertext letter is computed as c_i = (k_i − p_i) mod 26. Re-running the cipher on the ciphertext with the same key recovers the original.