In the transposition process, the letters of the plaintext are retained, but their sequence and position relative to one another are reversed, resulting in the ciphertext. For example, the plaintext WALD becomes the ciphertext ADWL or DLWA. There are several variants to increase security.
In the second cryptographic method, substitution, characters of the plaintext are replaced by other characters in the ciphertext; substituted. If the substitutioncipher is combined with the transposition cipher, the so-called product cipher is generated.