Information Security: Principles and Practices 2nd Edition by Jim Breithaupt, Mark S. Merkow

Exercise 12

Practicing Encryption Using Substitution

1. Encrypt the following using the substitution method with a rotate value of 13:

ALL GOOD MEN SHOULD COME TO THE AID OF THEIR COUNTRY

2. What result did you get?

Step 1 of 3

Creating cipher text using Substitution method

1. Substitution is a method of encryption wherein a plaintext is converted into a cipher text. This makes the data to be sent more secure as data in encrypted form is difficult to read and understand. Also it is hard to decode.

In substitution method, the basic idea is to replace the letters of the word (data) by some different letters such that it becomes unreadable. The ROT13 cipher is the substitution cipher that replaces each letter of the message by the 13^th letter in the alphabet.

Given the message "ALL GOOD MEN SHOULD COME TO THE AID OF THEIR COUNTRY", needs to be encrypted using Substitution method.