🔐 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/
│
├── app.py            # Caesar cipher implementation (CLI based)
├── LICENSE           # Project license
└── README.md         # Project documentation

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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

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🛠 Technologies Used

Technology	Role
Python 3	Core programming language
ord() / chr()	Character-to-ASCII conversion
Modular Arithmetic	Circular alphabet shifting

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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 Run the program

python app.py

4️⃣ Follow the prompts

• 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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🪪 Author

Shakal Bhau

GitHub: ShakalBhau0001

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