🔐 RSAxor — Hybrid Data Encryption/Decryption Tool

Developer: Brian Lorick
Organization: No/Label Security Services & Solutions
Version: 1.0.0
License: MIT License

---

📘 Overview

RSAxor is an educational C program that demonstrates the basic concept of hybrid encryption — combining RSA asymmetric encryption for key exchange and a simple XOR-based symmetric encryption (AES-like) for data protection.

This simulation works in any standard C compiler, including OnlineGDB, and does not require OpenSSL or any external libraries.

⚠️ Disclaimer: This tool is for educational purposes only and is not suitable for real cryptographic use.

---

🧠 Concept

Hybrid encryption systems use both:

1. Asymmetric encryption (RSA) — for securely exchanging a key.
2. Symmetric encryption (AES/XOR) — for encrypting actual data efficiently.

RSAxor simulates this process:

• RSA is used to encrypt a symmetric "AES" key.
• The "AES" encryption is performed using XOR operations.

---

🧩 Features

• 🔢 RSA key generation (p, q, e, d) using modular arithmetic
• 🔐 XOR-based symmetric cipher (AES-like simulation)
• 🧮 Modular exponentiation implementation for RSA math
• 💬 Interactive input/output for plaintext entry and encryption results
• 📜 Fully commented C source code for educational study

---

⚙️ Usage

🏗️ Build and Run

Using Makefile

make run

Manual Compilation

gcc -Wall -Iinclude src/main.c -o build/RSAxor
./build/RSAxor

---

💻 Sample Run (Example Output)

RSA Parameters:
  p = 61, q = 53
  n = 3233, phi = 3120
  e = 17, d = 2753

Enter plaintext message: hello

AES Encrypted (XOR) Ciphertext: 03 0E 07 07 04 
RSA Encrypted AES Key: 2496
RSA Decrypted AES Key: K

Decrypted Text: hello

---

🧩 File Structure

RSAxor/
├── src/        → source files (main.c)
├── include/    → header files (optional)
├── build/      → compiled output
├── tests/      → test files
├── Makefile    → build system
├── README.md   → documentation
├── LICENSE     → MIT license
└── .gitignore  → ignore build artifacts

---

🧾 Notes

• This project is designed to illustrate encryption concepts in a readable, portable C implementation.
• All cryptographic steps are simplified for educational clarity, not for security.
• Easily extendable for experimenting with other algorithms.

---

📄 License

This project is licensed under the MIT License.
© 2025 Brian Lorick — No/Label Security Services & Solutions