🔐 AES-GCM-Image-Cipher-GUI

AES-256-GCM Image Encryption & Decryption Toolkit (GUI Edition)

AES-GCM-Image-Cipher-GUI is a modern, password-based image encryption and decryption desktop application built entirely in Python (3.12.x compatible) using CustomTkinter. It allows end users (non-technical) to securely:

• Encrypt any image file using AES-256-GCM
• Decrypt .gcm encrypted files back to original format

All operations are performed locally with no network usage, ensuring full user privacy.

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✨ Key Philosophy

This project is designed with three core goals:

1. Security-first – AES-256-GCM with PBKDF2 key derivation
2. End-user friendly – clean GUI, sidebar navigation, minimal clicks
3. Modular architecture – crypto logic strictly separated from UI

This is not a toy project. The crypto core works independently and can be imported or reused without the GUI.

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🧩 Features

🔒 Encryption

Encrypt any image file using a password.

Features

• Supports PNG, JPG, BMP, GIF, WEBP and more
• Encrypted output: .gcm
• Random Salt + IV generated per file
• Original file extension preserved in header
• Timestamp in output filename (no overwrite)
• Password strength indicator

Use-case

Secure personal images, sensitive photos, private files

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🔓 Decryption

Decrypt .gcm encrypted files back to original format.

Features

• Restores original file extension automatically
• GCM Authentication Tag validates file integrity
• Detects wrong password or tampered files
• Clean error messages

Use-case

Restore encrypted images with correct password

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📁 Project Structure

AES-GCM-Image-Cipher-GUI/
│
├── core/
│   ├── __init__.py
│   └── crypto.py            # AES-256-GCM encryption / decryption logic
│
├── gui/
│   ├── __init__.py
│   ├── app.py               # Main window
│   ├── sidebar.py           # Left navigation sidebar
│   ├── encrypt_tab.py       # Encrypt tab UI
│   ├── decrypt_tab.py       # Decrypt tab UI
│   └── about_tab.py         # Crypto details + disclaimer
│
├── assets/                  # Screenshots
├── main.py                  # Entry point
├── requirements.txt
└── README.md

✔ Crypto logic (core/) and GUI (gui/) are strictly separated for maintainability.

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🔐 Cryptography Details

Component	Implementation
Encryption	AES-256-GCM (Authenticated)
Key Derivation	PBKDF2-HMAC-SHA256
Iterations	310,000
Salt	16 bytes (random per file)
IV	12 bytes (random per file)
Auth Tag	128-bit GCM tag
Output Extension	.gcm

✔ GCM Authentication Tag detects any tampering — wrong password or modified file is immediately rejected.

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🖥️ GUI Design

• Built with CustomTkinter
• Sidebar navigation (Encrypt / Decrypt / About)
• Password strength indicator
• Show / Hide password toggle
• Progress bar with background threading
• Status log with timestamps
• Dark / Light theme toggle
• Designed for non-technical users

Fully tested on:

• Python 3.12.10
• Windows 10 / 11

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🚀 Getting Started

1️⃣ Clone Repository

git clone https://github.com/ShakalBhau0001/AES-GCM-Image-Cipher-GUI.git
cd AES-GCM-Image-Cipher-GUI

2️⃣ Install Dependencies

pip install -r requirements.txt

3️⃣ Run Application

python main.py

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📦 requirements.txt

cryptography
customtkinter
pillow

No hidden or unnecessary dependencies.

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⚙️ How It Works

1️⃣ Key Derivation

• Password → PBKDF2-HMAC-SHA256 (310,000 iterations) → 32-byte AES-256 key

2️⃣ Encryption

• Random 16-byte Salt and 12-byte IV generated
• File encrypted using AES-256-GCM
• Encrypted file structure:

[MAGIC 6B] [SALT 16B] [IV 12B] [ext-len 1B] [ext NB] [ciphertext + 16B GCM tag]

3️⃣ Decryption

• Validates MAGIC header
• Extracts Salt, IV, and original extension
• Re-derives AES key using password + salt
• GCM tag verifies integrity before decryption
• Restores original file

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⚠️ Common Errors

Error	Reason
Wrong password	Decryption fails — GCM tag mismatch
Invalid file	MAGIC header missing
Tampered file	GCM authentication tag invalid
Wrong extension	Must select a .gcm file to decrypt

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🛣️ Roadmap

• Drag-and-drop file support
• Folder encryption support
• Progress bar for large files
• PyInstaller standalone builds
• Linux & macOS packaging

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⚠️ Security Disclaimer

This project is intended for educational and research purposes.

While it uses modern cryptographic primitives, it has not undergone formal security audits. Do not use it for protecting high-value or life-critical data.

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🪪 Author

Developer: Shakal Bhau

GitHub: ShakalBhau0001

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"Encryption should be powerful — but never complicated for the user."