C-Project-Encryption-Decryption

A basic C project for encrypting and decrypting text using custom or standard algorithms.

Caesar Cipher - Encryption & Decryption in C

This is a basic C language project that implements encryption and decryption using the Caesar Cipher technique. It allows you to generate alphabetic keys and perform secure message transformations by shifting characters based on a given key.

Features

• Encrypt plain text using Caesar Cipher
• Decrypt cipher text using Caesar Cipher
• Alphabetic key generation and usage
• Supports both uppercase and lowercase characters
• Ignores non-alphabetic characters (e.g., numbers, punctuation)
• Simple, beginner-friendly code in C

What is Caesar Cipher?

The Caesar Cipher is a basic encryption technique where each letter in the plain text is shifted by a fixed number of positions in the alphabet.
Example with key = 3:
Plain Text: HELLO → Cipher Text: KHOOR

How to Run

1. Compile the code (using GCC or any C compiler):
   gcc main.c -o caesar

2. Run the program:
   ./caesar

3. Follow the prompts to enter:

   • The message to encrypt/decrypt
   • The shift key (in my file key is given by user itself and same key use for decryption)

Learn More

This project is ideal for:

• Beginners learning C programming
• Understanding classical cryptography
• Exploring string manipulation and ASCII operations