RC4

A simple implementation of the RC4 (Rivest Cipher 4) stream cipher.

Overview

RC4 is a symmetric stream cipher designed by Ron Rivest. It generates a pseudorandom keystream that is XORed with plaintext to produce ciphertext. The same operation is used for decryption.

This repository provides a minimal and easy-to-understand RC4 implementation for educational and experimental purposes.

Features

• RC4 Key Scheduling Algorithm (KSA)
• RC4 Pseudo-Random Generation Algorithm (PRGA)
• Encryption and decryption support
• Lightweight and dependency-free

How It Works

1. Key Scheduling Algorithm (KSA)
   Initializes a 256-byte state array using the provided key.

2. Pseudo-Random Generation Algorithm (PRGA)
   Generates the keystream byte-by-byte from the internal state.

3. Encryption / Decryption
   Each byte of plaintext or ciphertext is XORed with the generated keystream.

Since RC4 is symmetric, the same function is used for both encryption and decryption.

Usage

Clone the repository

git clone https://github.com/v1rtu3x/Rc4.git
cd Rc4

Security Notice

RC4 is considered cryptographically insecure and should not be used in production systems. This implementation is intended for learning and experimentation only.