Master Substitution Cipher in Java: Encrypt & Decrypt Easily 🔐

Learn how to implement a substitution cipher encryption and decryption program in Java. This guide provides a step-by-step guide to creating a Java program that encrypts and decrypts messages using a substitution cipher algorithm.
---
Disclaimer/Disclosure: Some of the content was synthetically produced using various Generative AI (artificial intelligence) tools; so, there may be inaccuracies or misleading information present in the video. Please consider this before relying on the content to make any decisions or take any actions etc. If you still have any concerns, please feel free to write them in a comment. Thank you.
---
Substitution ciphers are one of the simplest forms of encryption, where each letter in the plaintext is replaced by another letter according to a fixed substitution scheme. In this guide, we'll walk through the steps to create a Java program for both encryption and decryption using a substitution cipher.

Encryption Program

First, let's create the encryption program. Here's the step-by-step guide:

Create a SubstitutionCipher class: This class will contain methods for both encryption and decryption.

Define a substitution key: This is a mapping of each letter in the alphabet to its corresponding substitution letter. For example, 'A' might be substituted with 'F', 'B' with 'X', and so on.

Implement the encryption method: Iterate through the plaintext message and substitute each letter according to the key. Maintain the case of each letter during substitution.

Output the encrypted message: Print or return the encrypted message.

Decryption Program

Now, let's create the decryption program:

Implement the decryption method: Similar to encryption, iterate through the encrypted message and substitute each letter back to its original letter according to the key.

Output the decrypted message: Print or return the decrypted message.

Sample Code

[[See Video to Reveal this Text or Code Snippet]]

This Java program demonstrates a basic implementation of a substitution cipher encryption and decryption algorithm. Feel free to modify the substitution key for different encryption schemes.