PDF Sentinel

A stealth desktop tool for legal teams to hash, stamp, and verify PDF document integrity.

Features

• Single File Stamp - Drag-and-drop a PDF to instantly hash and stamp it
• Batch Processing - Process multiple files or entire folders at once
• Folder Watch - Auto-stamp new PDFs dropped into a watched folder
• Verification - Re-check stamped PDFs to confirm integrity
• Visual Seal - Embeds a visible badge on the first page
• Print Reports - Generate printable verification reports

Installation

1. Create a virtual environment:

python -m venv venv
venv\Scripts\activate  # Windows

2. Install dependencies:

pip install -r requirements.txt

3. Run the application:

cd src
python main.py

Building Executable

pyinstaller build.spec

The executable will be created in the dist/ folder.

Project Structure

sentinel/
├── src/
│   ├── main.py              # Entry point
│   ├── app.py               # Main window
│   ├── components/          # UI widgets
│   │   ├── drop_zone.py     # Drag-and-drop widget
│   │   ├── batch_view.py    # Batch processing table
│   │   ├── watch_view.py    # Folder watch panel
│   │   └── verify_view.py   # Verification view
│   ├── core/                # Core logic
│   │   ├── hasher.py        # SHA256 hashing
│   │   ├── stamper.py       # PDF stamping
│   │   ├── verifier.py      # Integrity verification
│   │   └── watcher.py       # Folder monitoring
│   ├── utils/               # Utilities
│   │   ├── pdf_utils.py     # PDF helpers
│   │   └── report.py        # Report generation
│   └── assets/
│       └── styles.qss       # Qt stylesheet
├── requirements.txt
├── build.spec
└── README.md

How It Works

1. Hashing: SHA256 hash is calculated from the original PDF content
2. Embedding: Hash + timestamp are embedded in PDF metadata
3. Sealing: A visual verification badge is added to page 1
4. Verification: Re-calculates hash and compares to stored value

Tech Stack

• Python 3.11+
• PyQt6 - Modern GUI framework
• PyMuPDF (fitz) - PDF manipulation
• watchdog - Folder monitoring
• reportlab - Report generation
• PyInstaller - Executable packaging

License

MIT License - Free for personal and commercial use.

Support

This support will kept me going for developing more open source and free software.

Built with 🔐 by Sentinel