PrivacyFirewall

👋 If you're trying PrivacyFirewall, please star the repo!

It helps others discover the project and motivates development. Takes 2 seconds → ⭐ (top right)

Stop AI Data Leaks Before They Happen
100% Local • Zero Server • Full Control

---

The Problem

Every day, sensitive data gets leaked to AI chatbots:

• 📧 Customer emails pasted into ChatGPT for summarization
• 🔑 API keys accidentally included in code snippets
• 👤 Employee names shared in meeting notes
• 💳 Credit card numbers copied from support tickets
• 🏠 Home addresses in shipping data analysis

Traditional DLP tools don't protect AI chat interfaces. PrivacyFirewall does.

---

The Solution

PrivacyFirewall intercepts sensitive data before it reaches AI tools — running entirely in your browser with no external servers.

Key Features

Feature	Description
🛡️ Paste Protection	Blocks sensitive pastes with a confirmation modal
⌨️ Real-time Typing Detection	Warns as you type sensitive data
🧠 Local AI Detection	BERT NER model runs in-browser via ONNX/WASM
⚙️ Configurable Rules	Enable/disable specific PII types, set block vs warn
🌐 Site Management	Protect ChatGPT, Claude, Gemini, Copilot, and more
🔒 Zero Data Transmission	Nothing ever leaves your machine

---

How It Works

graph TD
    A[User Pastes/Types Text] -->|Intercept| B(Content Script)
    B -->|Layer 1| C{Regex Scan}
    C -->|Match Found| D{Block or Warn?}
    D -->|Block| E[🛑 Show Modal]
    D -->|Warn| F[⚠️ Show Banner]
    C -->|No Match| G{AI Engine Ready?}
    G -->|Yes| H[ONNX Model in Browser]
    H -->|Entities Found| D
    H -->|Clean| I[✅ Allow]
    G -->|No| I

    style E fill:#dc2626,color:#fff
    style F fill:#f59e0b,color:#fff
    style I fill:#22c55e,color:#fff

Loading

Two-Layer Protection

1. Instant Regex Layer — Catches obvious patterns (emails, credit cards, API keys) in milliseconds
2. AI Layer — BERT Named Entity Recognition detects names, organizations, and locations that regex misses

Both layers run 100% locally in your browser. No Python server. No API calls. No cloud.

---

Quick Start

Option 1: Download & Install (No Code Required)

Perfect for trying it out — takes 30 seconds

1. Download the latest release:

   

2. Unzip the downloaded file

3. Install in Chrome:

   • Go to chrome://extensions
   • Enable Developer mode (toggle in top right)
   • Click Load unpacked
   • Select the unzipped folder

4. Done! Visit ChatGPT and try pasting:

   Contact john.doe@company.com or call 555-123-4567
   

---

Option 2: Build from Source (For Developers)

Click to expand developer instructions

1. Clone the repository

   git clone https://github.com/ArnabKar/privacy-firewall.git
   cd privacy-firewall

2. Build the extension

   cd src/extension
   npm install
   node build.js

3. Load in Chrome

   • Navigate to chrome://extensions
   • Enable Developer mode (top right)
   • Click Load unpacked
   • Select the src/extension/dist folder

---

Screenshots

Paste Blocked Sensitive data detected with highlighting	Typing Warning Real-time detection as you type
Extension Popup Quick status and settings access	Settings Page Full control over detection rules

---

Detection Coverage

Regex Detection (Instant)

Type	Examples
📧 Email	user@example.com
📱 Phone	555-123-4567, +1 (555) 123-4567
💳 Credit Card	4532-0151-1283-0366
🔢 SSN	123-45-6789
🔑 AWS Keys	AKIAIOSFODNN7EXAMPLE
🎫 JWT Tokens	eyJhbGciOiJIUzI1NiJ9...
🔐 Private Keys	-----BEGIN RSA PRIVATE KEY-----
🌐 IP Addresses	192.168.1.1
📍 MAC Addresses	00:1A:2B:3C:4D:5E
🏠 US Addresses	123 Main St, New York, NY 10001

AI Detection (BERT NER)

Entity Type	Examples
👤 PERSON	John Smith, Dr. Sarah Thompson
🏢 ORGANIZATION	Acme Corp, Goldman Sachs
📍 LOCATION	New York, Silicon Valley

---

Configuration

Settings Page

Access via the extension popup → Open Settings

• PII Rules: Enable/disable detection for each type
• Block vs Warn: Choose blocking modal or warning banner
• Protected Sites: Manage which AI tools are protected
• AI Confidence: Adjust sensitivity threshold (0-100%)
• Behavior: Toggle real-time typing detection

Protected Sites (Default)

• ✅ ChatGPT (chat.openai.com, chatgpt.com)
• ✅ Claude (claude.ai)
• ✅ Gemini (gemini.google.com)
• ✅ Copilot (copilot.microsoft.com)
• ✅ Poe (poe.com)
• ✅ Grok (grok.com)
• ✅ DeepSeek (chat.deepseek.com)

---

Architecture

src/extension/
├── manifest.json          # Chrome MV3 manifest
├── background.js          # Service worker (message routing)
├── content-script.js      # Page injection (paste/typing interception)
├── offscreen.js           # AI model execution environment
├── offscreen.html         # Offscreen document container
├── lib/
│   └── transformer-detector.js  # BERT NER model wrapper
├── modules/
│   ├── config.js          # Regex patterns & constants
│   ├── scanner.js         # Detection orchestration
│   ├── settings.js        # Chrome storage management
│   ├── event-handlers.js  # Paste & input handlers
│   └── ui/
│       ├── modal.js       # Blocking modal component
│       ├── banner.js      # Warning banner component
│       └── styles.js      # Shadow DOM styles
└── ui/
    ├── popup.html/js/css  # Extension popup
    └── settings.html/js/css # Settings page

Technology Stack

• Extension: Chrome Manifest V3, ES Modules
• AI Runtime: ONNX Runtime Web (WASM)
• Model: Xenova/bert-base-NER-uncased via Hugging Face Transformers.js
• UI Isolation: Shadow DOM (no CSS conflicts with host pages)

---

Privacy & Security

What We DON'T Do

• ❌ Send data to external servers
• ❌ Log or store your text
• ❌ Use analytics or telemetry
• ❌ Make any network requests (except model download on first run)

What We DO

• ✅ Process everything locally in your browser
• ✅ Cache the AI model locally after first download
• ✅ Store settings in Chrome's encrypted sync storage
• ✅ Provide fully auditable open-source code

Verify yourself: Open DevTools → Network tab. You'll see zero outbound requests during detection.

---

Development

Build

cd src/extension
npm install
node build.js

Run Tests

node tests/content-script.test.js

Project Requirements

• Chrome 120+ (for Offscreen Documents API)
• Node.js 18+ (for building)

---

Troubleshooting

"AI Model Loading..." stays forever

• Check DevTools console for errors
• The model (~50MB) downloads on first run — may take a minute on slow connections
• Try clearing extension data and reloading

Extension doesn't detect on some sites

• Check if the site is in your protected sites list
• Some sites use iframes — detection may be limited
• Open an issue with the site URL

False positives/negatives

• Adjust AI confidence threshold in settings
• Some patterns (like short names) may not be detected
• Report edge cases as issues

---

Roadmap

• Firefox/Safari support
• Custom regex patterns via settings
• Redaction mode (replace vs block)
• Export/import settings
• Keyboard shortcuts
• Enterprise policy support

---

Contributing

PRs welcome! Please include:

• Browser version
• Steps to reproduce
• Expected vs actual behavior

---

License

MIT License — see LICENSE

---

Built for privacy. Runs locally. Open source.
Report Bug • Request Feature