Cipher

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.

The Autokey Cipher, invented by Blaise de Vigenère in the 16th century, is a form of polyalphabetic substitution cipher that improves on the traditional Vigenère cipher by incorporating the plaintext itself into the key. This cipher was designed to strengthen encryption by reducing repetitive patterns in the key, making it more resistant to frequency analysis. The concept of the Autokey Cipher builds on Vigenère's previous work and is part of what’s sometimes called the Vigenère family of ciphers.

The Alberti cipher, created by Leon Battista Alberti in the 15th century, is recognized as one of the earliest examples of a polyalphabetic substitution cipher. Alberti, an Italian Renaissance polymath, developed this cipher as a response to the need for stronger, more secure encryption methods that could withstand frequency analysis, a technique that had become effective against simpler monoalphabetic ciphers.

The Affine cipher is a type of substitution cipher rooted in modular arithmetic, which falls under the category of monoalphabetic ciphers. It has origins in classical cryptography, dating back to the use of basic substitution techniques by ancient civilizations. While there isn’t a single, clear creator or exact date for the invention of the affine cipher specifically, it embodies methods commonly attributed to early cipher systems used throughout history, such as by Roman and Greek scholars.

The Templar Cipher is a cryptographic method associated with the Knights Templar, a medieval Christian military order founded during the Crusades. It is one of the many historical ciphers that have been attributed to the Knights Templar, although the exact cipher they used remains a subject of debate and speculation.