The Beaufort Cipher is a polyalphabetic substitution cipher that was invented by Sir Francis Beaufort in the 19th century. The cipher is closely related to the Vigenère Cipher but works slightly differently. Unlike the Vigenère Cipher, the Beaufort Cipher uses a reversed encryption and decryption algorithm, which means the ciphertext is produced by reversing the order of the alphabets used in the Vigenère method.