
Cisco Certified CyberOps Associate 200-201 Certification Guide
By :

In this section, we will discuss the characteristics of various types of ciphers that are used within data encryption algorithms.
In each type of encryption algorithm (cipher), a secret key is used to ensure the message remains private. In a substitution cipher, the secret key is the shifting of a letter from the original message. This means the number of letters within the plaintext message does not change after it is passed through the cipher and becomes ciphertext.
To better understand how a substitution cipher works, let's take a look at a very well-known cipher, the Caesar cipher, which has been around for quite some time, and its encryption techniques are simply shifting the letter of the alphabet. As an example, let's take a sentence such as the quick brown fox jumps over the lazy dog as the plaintext message. Let's use ROT13 as the key, which is to rotate the letters of the alphabet by 13, such as A = N
, B = O
,...