🔐 Row–Column Transposition Cipher Implementation (Python)

A complete and educational Python implementation of the Row–Column Transposition Cipher encryption algorithm. This project demonstrates column-based permutation encryption and decryption using structured logic.

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

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🧱 Project Structure

row-column-transposition-python/
│
├── app.py            # Row–Column Transposition cipher implementation (CLI based)
├── LICENSE           # Project license
└── README.md         # Project documentation

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✨ Features

🔑 Keyword-Based Column Permutation

• Uses a keyword as the encryption key
• Determines column order based on alphabetical ranking
• Rearranges plaintext using column permutation
• Demonstrates structured transposition logic

🔒 Encryption

• Removes spaces before processing
• Arranges plaintext row-wise in a matrix
• Reorders columns according to keyword
• Reads column by column to generate ciphertext

🔓 Decryption

• Reconstructs the column structure using the same keyword
• Restores original row-wise message order
• Reverses the permutation algorithm accurately

🧮 Educational Focus

• Clean and readable logic
• Matrix-based column handling
• Ideal for beginners in cryptography
• No external dependencies

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🛠 Technologies Used

Technology	Role
Python 3	Core programming language
List & Matrix Logic	Column permutation handling

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📌 Purpose of This Project

This project is built to:

• Understand classical columnar transposition ciphers
• Learn permutation-based encryption logic
• Explore matrix-based cryptographic techniques
• Study reversible transformation algorithms

⚠️ 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/row-column-transposition-python.git

2️⃣ Navigate to the project folder

cd row-column-transposition-python

3️⃣ Run the program

python app.py

4️⃣ Follow the prompts

• Choose direction:
  • E → Encrypt
  • D → Decrypt
• Enter your message
• Enter keyword
• View the result

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🔎 Example

Encryption :

Encrypt or Decrypt (E/D): E
Enter message: MEET ME TOMORROW
Enter keyword: ZEBRA

Encrypted message: EMRMOETEWROTMEO

Decryption :

Encrypt or Decrypt (E/D): D
Enter message: EMRMOETEWROTMEO
Enter keyword: ZEBRA

Decrypted message: MEETMETOMORROWX

(Note: Padding character may appear during decryption.)

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⚠️ Limitations

• Not secure for real-world use
• Classical cipher (easily breakable)
• May include padding characters
• Removes spaces during processing
• CLI-based interaction only

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🌟 Future Improvements

• Preserve spaces and formatting
• Improve duplicate-letter handling in keywords
• Add frequency analysis support
• Add input validation enhancements
• Create GUI version
• Combine into a classical cryptography toolkit

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⚠️ Disclaimer

This implementation is created for educational and learning purposes only. The Row–Column Transposition Cipher is historically significant but cryptographically insecure and must not be used to protect real-world sensitive data.

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🪪 Author

Shakal Bhau

GitHub: ShakalBhau0001

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