Substitution

Keyboard Code, also known as Keyboard Cipher or Keyboard Encryption, is a simple and straightforward method of encrypting and decrypting messages using a keyboard layout as a reference. It is a type of substitution cipher, where each letter of the plaintext is replaced with a corresponding letter from the keyboard layout.

The Dorabella Cipher is a mysterious and elegant encrypted message created by English poet Edward Elgar for a close friend, Dora Penny, in 1897. It is a substitution cipher, a type of code where each letter in the plaintext is replaced with a different letter or symbol to conceal the original message.

A Digraph Cipher is a cryptographic technique that operates on pairs of letters (digraphs) rather than individual letters. It is a substitution cipher where each digraph in the plaintext is replaced by a corresponding digraph in the ciphertext according to a predefined rule or key.

Here's a general overview of how a Digraph Cipher works:

A Dice Cipher, also known as a Dice Cryptography or a Book Cipher, is a cryptographic technique that uses dice as a randomization tool to generate a series of numbers that correspond to words or characters in a pre-selected reference book. It is a form of polyalphabetic substitution cipher.

Here's a general overview of how a Dice Cipher works:

The Bifid Cipher is a Fractionating Transposition cryptographic technique that was invented by the French amateur cryptographer Félix Delastelle in 1901. It is a fractionating transposition cipher that combines elements of both substitution and transposition methods.

The Bifid Cipher operates on a square grid known as the Polybius square or Polybius checkerboard. This square consists of a 5x5 grid containing the letters of the alphabet (usually excluding the letter 'J').

The encryption process in the Bifid Cipher involves the following steps: