Text Encryptor and Decryptor in C

This project is a simple text encryption and decryption program implemented in C. It uses a substitution cipher, where each letter in the plaintext is replaced by a letter from a key that consists of 26 unique alphabetic characters.

Features

• Key Validation: Ensures the key is exactly 26 unique alphabetic characters.
• Encrypt Messages: Replaces plaintext characters using the substitution cipher.
• Decrypt Messages: Recovers the original message from a ciphertext using the same key.
• Case Sensitivity: Preserves the case (uppercase/lowercase) of letters during encryption and decryption.
• Handles Non-Alphabetic Characters: Leaves spaces, numbers, and special characters unchanged.

Installation

To get a local copy of the project, follow these steps:

1. Clone the repository: git clone https://github.com/sarpaltinok/Text-Encryptor-and-Decryptor-in-C.git
2. Navigate to the project directory: gcc -o encrypt_decrypt main.c
3. Run the program: ./encrypt_decrypt

Usage

• Enter a key (26 unique alphabetic characters).
• Choose to either encrypt or decrypt a message.
• Enter the message and get the output

Example Key: QWERTYUIOPLKJHGFDSAZXCVBNM

License

This project is licensed under the MIT License - see the LICENSE file for details.