Chat Encryption Viewer

Open-source proof-of-concept demonstrating encrypted chat storage in chuk_chat

🔒 What is This?

This is a transparency tool that demonstrates how chats are encrypted in the chuk_chat application. It allows users to:

1. Login with their chuk_chat credentials
2. See your real chats from the chuk_chat app
3. View encrypted data exactly as it's stored in the database
4. Toggle between encrypted and decrypted views
5. Verify that encryption is working properly with your actual chat data

🎯 Purpose

This app exists to prove to users that:

• ✅ Their chats are encrypted client-side
• ✅ The server never sees plaintext messages
• ✅ Only the user's password can decrypt their chats
• ✅ Encryption uses industry-standard algorithms

🔐 Encryption Details

Algorithms Used

Component	Algorithm	Details
Encryption	AES-256-GCM	Advanced Encryption Standard with 256-bit keys
Key Derivation	PBKDF2-HMAC-SHA256	600,000 iterations (very secure!)
Nonce Generation	Cryptographically Secure Random	12-byte nonces for GCM mode
MAC	GCM built-in authentication	Ensures data integrity

How It Works

1. User enters password
   ↓
2. PBKDF2 derives encryption key (600,000 iterations)
   ↓
3. Key is stored locally (never sent to server)
   ↓
4. Messages are encrypted with AES-256-GCM before storage
   ↓
5. Encrypted payload includes:
   - Version number
   - Nonce (random)
   - Ciphertext (encrypted message)
   - MAC (authentication tag)

Example Encrypted Message

When you toggle to "Encrypted" view, you'll see something like this:

{
  "v": "1",
  "nonce": "8Kx2mPqR3nF5tLwZ",
  "ciphertext": "5YzN8pQr2hK9xM3vB7wL...",
  "mac": "1FgT4hJ6kN9pR2sV5yB8..."
}

This is exactly how your chats are stored on your device!

🚀 Getting Started

Prerequisites

• Flutter 3.0 or higher
• An account on chuk_chat (or the demo Supabase instance)

Installation

# Clone the repository
git clone https://github.com/1337-Corp/chat_encryption_viewer.git
cd chat_encryption_viewer

# Get dependencies
flutter pub get

# Run the app
flutter run

Usage

1. Sign in with your chuk_chat email and password
2. View demo chats with sensitive information
3. Toggle between "Encrypted" and "Decrypted" views
4. Inspect the encryption format

📸 Screenshots

Login Screen

Clean, simple authentication interface.

Encrypted View

Shows the raw encrypted JSON as it's stored on your device.

Decrypted View

Shows the plaintext message (only visible with your password).

🔬 Code Structure

lib/
├── main.dart                    # Main app with login and viewer UI
├── encryption_demo_service.dart # Simplified encryption service
└── supabase_config.dart         # Backend configuration

Key Files

encryption_demo_service.dart

Demonstrates the same encryption used in chuk_chat:

• PBKDF2 key derivation (600,000 iterations)
• AES-256-GCM encryption/decryption
• Secure random nonce generation

main.dart

Simple Flutter app that:

• Authenticates users
• Creates demo chats
• Shows encrypted vs decrypted views

🛡️ Security Features

✅ Client-Side Encryption

• All encryption happens on your device
• Server only stores encrypted data
• Your password never leaves your device

✅ Key Derivation

• PBKDF2 with 600,000 iterations
• Makes brute-force attacks impractical
• Salt is unique per user

✅ Authentication

• GCM mode provides built-in authentication
• Detects any tampering with encrypted data
• Prevents bit-flipping attacks

✅ Random Nonces

• Each message uses a unique random nonce
• Prevents pattern analysis
• Ensures same message encrypts differently each time

🤝 Contributing

This is an open-source transparency tool! Contributions are welcome:

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

⚠️ Disclaimer

This is a demonstration tool to show how encryption works. It uses simplified key storage (SharedPreferences) for demo purposes. The main chuk_chat app uses more secure storage (flutter_secure_storage).

🔗 Related Projects

• chuk_chat - The main chat application

❓ FAQ

Q: Is this the same encryption as chuk_chat?

A: Yes! Same algorithms (AES-256-GCM, PBKDF2), same parameters (600k iterations), same format.

Q: Can the server read my messages?

A: No! Encryption happens on your device. The server only sees encrypted blobs.

Q: What if I forget my password?

A: Your data cannot be decrypted without your password. This is by design for security.

Q: Why 600,000 PBKDF2 iterations?

A: This makes brute-force attacks very expensive. Each password guess takes ~0.5 seconds on modern hardware.

Q: Can I verify the encryption myself?

A: Yes! That's the whole point of this app. You can see the encrypted data and verify it matches the encrypted view.

📞 Support

If you have questions or concerns about encryption in chuk_chat:

• Open an issue on this repository
• Review the source code (it's open source!)
• Test it yourself with this viewer app

🙏 Acknowledgments

• Supabase - Backend infrastructure
• Cryptography Package - Dart cryptography library
• Flutter - UI framework

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Made with ❤️ for transparency and privacy