🔐 Secure File Encryption & Decryption Tool

Secure File Encryption & Decryption Tool is a Python-based desktop application that allows users to securely encrypt and decrypt files using modern cryptographic standards. The application uses AES-256-GCM for encryption along with PBKDF2 (SHA-256) for secure password-based key derivation, ensuring strong protection against unauthorized access. A modern, responsive GUI is provided using CustomTkinter.

📌 Features

• AES-256-GCM authenticated encryption
• Secure password-based key derivation using PBKDF2 + SHA-256
• Live password strength meter with real-time progress bar
• File encryption and decryption with .enc extension
• Secure random salt and nonce generation for each file
• Modern, responsive GUI with Dark/Light mode
• Show/Hide password toggle
• Multi-threaded operations to keep UI responsive
• Proper error handling and user-friendly alerts
• Cross-platform support (Windows, macOS, Linux)

🛠️ Technologies Used

• Python 3.10+
• CustomTkinter (GUI Framework)
• Cryptography Library
• AES-256-GCM (Symmetric Encryption)
• PBKDF2 (Password-Based Key Derivation)
• SHA-256 Hashing
• Tkinter File Dialogs
• Multi-threading

⚙️ Installation Guide

1️⃣ Install Python

Check if Python is installed:

python --version

If not installed, download and install Python 3.10+ from: Python

⚠️ Important: During installation, check "Add Python to PATH"

2️⃣ Clone or Download the Project

git clone https://github.com/SyedShaheerHussain/Secure-File-Encryption-Decryption-Tool-GUI-.git

cd Secure File Encryption & Decryption Tool

Or manually download and extract the project folder.

3️⃣ (Optional) Create a Virtual Environment

python -m venv venv

Activate it:

Windows

venv\Scripts\activate

macOS / Linux

source venv/bin/activate

4️⃣ Install Required Packages

pip install cryptography customtkinter

Verify installation:

python -c "import cryptography, customtkinter"

▶️ How to Run the Application

python mainapp.py

After running, the GUI window will open.

🔐 How Encryption Works

1. User selects a file using the Browse File button.

2. User enters a password.

3. Password is validated using a live password strength meter.

4. A secure encryption key is derived using PBKDF2 + SHA-256.

5. AES-256-GCM encrypts the file with a random salt and nonce.

6. Encrypted file is saved with .enc extension.

7. Success message displays encrypted file location.

🔓 How Decryption Works

1. User selects an encrypted .enc file.

2. User enters the same password used for encryption.

3. The encryption key is regenerated using PBKDF2.

4. AES-256-GCM decrypts the file.

5. Original file is restored if password is correct.

6. Error message is shown for incorrect passwords or corrupted files.

🔑 Password Strength Meter

The application includes a real-time password strength meter based on:

• Password length

• Uppercase characters

• Lowercase characters

• Digits

• Special symbols

• Strength Levels:

• Weak (Red)

• Medium (Yellow)

• Strong (Orange)

• Very Strong (Green)

• Weak and medium passwords are blocked during encryption.

🎨 GUI Overview

• Sidebar navigation (Encrypt, Decrypt, Settings, About)

• Modern buttons, spacing, and typography

• Responsive layout

• Dark / Light mode toggle

• Password visibility toggle

• Progress bars for encryption feedback

🧪 Security Design Highlights

• AES-256-GCM ensures confidentiality and integrity

• Random salt prevents rainbow-table attacks

• Nonce ensures unique encryption per file

• Keys are never stored on disk

• Passwords are never saved in plaintext

• Encryption logic separated from GUI logic

• Industry-standard cryptography practices followed

🖥️ Create Standalone Executable (Optional)

Install PyInstaller:

pip install pyinstaller

Build executable:

pyinstaller --onefile --windowed mainapp.py

The executable will be available in the dist/ folder.

📚 Learning Outcomes

• Understanding of symmetric encryption (AES)

• Secure password-based key derivation

• GUI development with CustomTkinter

• Secure file handling in Python

• Multi-threaded desktop applications

• Real-world cryptography implementation

• Secure software design principles

🚀 Future Enhancements

1. Folder encryption support

2. Secure file deletion (shredding)

3. Master password login system

4. Key rotation support

5. Hybrid encryption (AES + RSA)

6. Cloud storage integration

7. Two-factor authentication (2FA)

8. Auto-lock and retry limits

👨‍💻 Author

Developed by (© Syed Shaheer Hussain) A professional Python-based cryptography and secure software project.

📄 License

Important

This project is intended for educational and academic purposes. Use responsibly and follow local data protection laws.

⭐ Final Note

Note

This project demonstrates practical implementation of modern encryption standards with a professional GUI. It is suitable for Final Year Projects (FYP), portfolio showcases, and learning secure software development.