Transposition

The Grid Transposition Cipher is a method of encryption that involves rearranging the characters of a message based on a predetermined grid pattern. It is a type of transposition cipher, where the original letters of the plaintext are maintained, but their positions are altered to create the ciphertext.

The Columnar cipher is a transposition cipher that rearranges the characters of a message by writing them in a grid format and then reading them column by column in a specific order. It does not change the actual characters but alters their order to create the ciphertext.

Here's how the Columnar cipher works:

Fractionating Transposition Cipher

The Bifid Cipher is a 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: