Aegis Messenger 📡🔐

Secure Android messenger powered by Signal Protocol, SQLCipher, JWT, WebSocket, and advanced client protection mechanisms.

✨ Key Features

• End-to-end encryption (Signal Protocol: X3DH, Double Ratchet)
• Encrypted database (SQLCipher + Android Keystore)
• Secure key storage (hardware-backed Keystore)
• Server communication via REST & WebSocket
• Private contact discovery (SGX)
• Sealed Sender (sender anonymity)
• Anti-analysis mechanisms (root, debug, ptrace detection)
• Duress PIN (fake environment / secure wipe)
• App icon hiding mode
• Safety Numbers (key verification with QR)
• Encrypted group chats & file sharing
• Threat modeling using STRIDE

🛠️ Project Architecture

• crypto/ – Signal Protocol logic
• network/ – server comms, SGX, Sealed Sender
• security/ – Keystore, SQLCipher, root/debug detection, JWT, Duress PIN
• ui/ – activities, views, Safety Numbers, LockScreen
• group/ – group chat logic
• file/ – file sharing
• db/ – Room encrypted database

⚡ Quick Start

1. Open the project in Android Studio.
2. Install dependencies (Gradle).
3. Build and run on Android device (minSdk 23).
4. Run unit tests: ./gradlew test

📂 Backend (demo)

• Sample backend lives in backend/ folder
• Run: cd backend && npm install && npm start
• REST: publish/retrieve keys, send messages
• WebSocket: push messages in real-time, JWT auth
• Data persistence: in-memory (for testing only)

🔒 Security

• Keys always stored in hardware-backed Keystore
• SQLCipher for all local data
• Code obfuscation (R8), root/debug/ptrace detection
• Duress PIN – secure wipe & reset functionality
• STRIDE threat model in ui/ThreatModeling.kt

🔄 Message Flow Example

1. Message composed in UI (ChatActivity.kt)
2. Encrypted with Signal (SignalSessionManager.kt)
3. Sent via REST/WebSocket (ServerCommunicator.kt)
4. Stored in encrypted Room database (MessageDao.kt)

📊 Requirements

• Android 6.0+ (minSdk 23)
• Node.js (for demo backend)

⚖️ License

Demo project – open for further development and security audit.

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📧 Contact: If you have questions or want to contribute, open an issue or reach out via GitHub.