🔐 Caesar Cipher Implementation (Python)

A simple and educational Python implementation of the Caesar Cipher encryption algorithm. This project demonstrates left and right shifting encryption and decryption using basic character manipulation and modular arithmetic.

It is created as a learning and academic project to understand how classical cryptography works internally, not as a production-ready security system.

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🧱 Project Structure

caesar-cipher-python/
│
├── assets/           # Screenshots
├── app.py            # Basic CLI version
├── interactive.py    # Rich-powered CLI
├── requirements.txt  # Dependencies
├── LICENSE
└── README.md

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✨ Features

🔁 Left & Right Shift Support

• User can choose:
  • L → Left Shift
  • R → Right Shift
• Demonstrates both encryption directions for learning clarity

🔒 Encryption

• Encrypts alphabetic characters using a shift key
• Preserves uppercase and lowercase letters
• Keeps spaces and special characters unchanged

🔓 Decryption

• Automatically decrypts using the opposite shift direction
• Verifies correctness of the algorithm

🧮 Educational Focus

• Clean and readable logic
• Uses modular arithmetic (% 26)
• Ideal for beginners in cryptography
• No external dependencies

🎨 Rich CLI (Interactive Mode)

• Beautiful colored terminal UI using Rich
• Structured panels for output display
• Interactive prompts with validation
• Enhanced user experience compared to standard CLI

⚡ Dual Mode Support

• 🧼 Basic CLI → Lightweight, no dependencies
• 🎨 Rich CLI → Enhanced UI with colors and panels

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🛠 Technologies Used

Technology	Role
Python 3	Core programming language
ord() / chr()	Character-to-ASCII conversion
Modular Arithmetic	Circular alphabet shifting
Rich	Styled CLI, colors, panels

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📌 Purpose of This Project

This project is built to:

• Understand classical cryptography
• Learn Caesar Cipher encryption & decryption
• Practice modular arithmetic concepts
• Visualize left vs right shifting
• Strengthen Python string manipulation skills

⚠️ This project is intended strictly for learning and demonstration purposes.

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▶️ How to Run

1️⃣ Clone the repository

git clone https://github.com/ShakalBhau0001/caesar-cipher-python.git

2️⃣ Navigate to the project folder

cd caesar-cipher-python

3️⃣ Install Dependencies

pip install rich

OR

pip install -r requirements.txt

4️⃣ Running the Project

Basic CLI Version

python app.py

Rich Interactive Version

python interactive.py

5️⃣ Follow the prompts for Basic CLI Version

• Enter a message
• Enter a shift key (integer)
• Choose direction:
  • L for Left Shift
  • R for Right Shift
• View encrypted and decrypted output

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🔎 Example

Enter message: HELLO
Enter shift key: 3
Choose direction (L = Left, R = Right): R

Encrypted Message: KHOOR
Decrypted Message: HELLO

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⚠️ Limitations

• Not secure for real-world use
• Classical cipher (easily breakable)
• No brute-force protection
• CLI-based interaction only

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🌟 Future Improvements

• Add brute-force mode
• Add English frequency scoring
• Add input validation for shift values
• Add file encryption support
• Create GUI version

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⚠️ Disclaimer

This implementation is created for educational and learning purposes only. The Caesar Cipher is a historically important but insecure encryption method and must not be used to protect real-world sensitive data.

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📸 Preview

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🪪 Author

Developer: Shakal Bhau

GitHub: ShakalBhau0001

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⭐ Support

If you like this project, consider giving it a ⭐ on GitHub!

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