Computer-Network-and-Security

Encryption and Decryption Algorithms in C

This repository contains C implementations of various encryption and decryption algorithms, including Hill Cipher, Columnar Transposition, Vigenère Cipher, and Caesar Cipher.

Table of Contents

• Introduction
• Algorithms Implemented
• Usage
• Contributing
• License

Introduction

Encryption is the process of converting plaintext into ciphertext to secure it from unauthorized access. Decryption is the reverse process of converting ciphertext back into plaintext. This repository provides implementations of popular encryption and decryption algorithms in C language.

Algorithms Implemented

• Hill Cipher: A polygraphic substitution cipher based on linear algebra. It operates on blocks of plaintext letters and uses matrix multiplication for encryption and decryption.
• Columnar Transposition: A simple transposition cipher where the plaintext is reordered according to a specified columnar arrangement. The key determines the order of the columns.
• Vigenère Cipher: A method of encrypting alphabetic text by using a simple form of polyalphabetic substitution. It uses a keyword to shift each letter of the plaintext by different amounts.
• Caesar Cipher: One of the simplest and most widely known encryption techniques. It shifts each letter of the plaintext by a fixed number of positions in the alphabet.

License

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