- Replace libsodium with pure Web Crypto X25519 ECDH for key exchange
- Sealed-box pattern: ephemeral keypair + HKDF + AES-256-GCM for each recipient
- Store encrypted conversation key per-user so each party decrypts with their own private key
- PBKDF2-derived master key wraps X25519 private key (pkcs8) server-side for cross-device login
- Fix health endpoint ordering so it never hits auth middleware (401 bug)
- Fix postgres port exposure in docker-compose for backend connectivity
- Fix DrivePage react-query v5 onSuccess → useEffect migration
- Fix MessagesPage: use <Link> instead of <a href> to avoid page reload losing in-memory keys
- Fix formatDistanceToNow crash on WebSocket messages lacking sent_at (add fallback + null guard)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Zero-knowledge architecture: all encryption/decryption client-side via Web Crypto API
- AES-GCM 256 for messages, files, and key wrapping; PBKDF2 for password-based key derivation
- Node.js/TypeScript backend: JWT auth with refresh rotation, argon2id passwords, TOTP 2FA
- PostgreSQL schema: encrypted blobs only, server never stores plaintext
- Real-time messaging via WebSocket relay (server routes ciphertext, cannot read it)
- Encrypted file upload/download with per-file keys wrapped by user master key
- React PWA frontend: Vite + Tailwind + service worker for offline support
- Docker Compose: postgres + backend + frontend + nginx with TLS
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>