Whisper by Noctis Privacy

A private, post-quantum, decentralized peer-to-peer messenger for macOS.

No central server, no operator-run relay, no directory authority anyone can subpoena. The transport is I2P — a fully decentralized, garlic- routed overlay network whose router directory (NetDB) is itself a peer-to-peer DHT, so there is no global registry of users to enumerate. Peers connect directly to each other through anonymous tunnels built across that mesh. Cryptography is hybrid post-quantum and every session is protected by both classical X25519 and ML-KEM-1024, so an attacker has to break both legs to recover a key. Local storage is SQLCipher anchored to a hardware-bound seed in the macOS Keychain (kSecAttrAccessibleWhenUnlockedThisDeviceOnly, non-syncable). A clone of the database file on another machine cannot be opened without the original Mac's Keychain.

For day-to-day usage — adding contacts, what status indicators mean, moving devices, troubleshooting — see docs/GUIDE.md. For the architecture and the threat model, see WHITEPAPER.md. For the high-level version, see LITEPAPER.md.

Install

Apple Silicon Macs running macOS 12+. Single command — Homebrew will auto-tap on the fully-qualified cask reference:

brew install --cask jetp1ane/noctis-whisper/noctis-whisper

Every release is signed with an Apple Developer ID and notarized by Apple's notary service, so Gatekeeper opens the app cleanly even on direct .dmg downloads. (The shorter brew install --cask noctis-whisper form will work after submission to homebrew/homebrew-cask clears review.)

Status

v1.0.0 — first stable release, available via Homebrew Cask.

Whisper has been through multiple rounds of independent security review covering the cryptographic protocol, the local SQLCipher vault, transport-layer integrity, and platform hardening. Findings were remediated and the fixes are covered by regression tests that run on every push.

Distribution: signed with an Apple Developer ID and notarized by Apple's notary service, with macOS Hardened Runtime and App Sandbox both in force. Direct .dmg downloads pass Gatekeeper cleanly.

Stack

• Backend: Rust (Tauri v2) — crypto, I2P transport, SQLCipher, macOS Keychain glue
• Frontend: React + TypeScript + Tailwind, single window, dark/light
• Database: SQLCipher 4 via rusqlite with bundled-sqlcipher
• Crypto:
  • X25519 (x25519-dalek), Ed25519 (ed25519-dalek)
  • ML-KEM-1024 (pqcrypto-mlkem) for hybrid post-quantum key exchange
  • ChaCha20-Poly1305 (chacha20poly1305) AEAD
  • HKDF-SHA256, BLAKE2b, Argon2id (256 MiB / 4 iter / 4 lanes)
  • All key buffers wrapped in zeroize
• Transport: bundled i2pd subprocess on a randomized SAM port, destination minted at first vault unlock and persisted in SQLCipher.

Project layout

src-tauri/src/
  crypto/         keys, vault, pqx3dh, ratchet, message_crypto,
                  sender_key, sealed, secure_enclave, safety_numbers,
                  config_manifest, bundle, seed
  transport/
    i2p/          manager (i2pd lifecycle), sam (SAM v3 client),
                  connection, framing, queue, dispatch, lifecycle,
                  destination, runtime
    mailbox.rs    BLAKE2b mailbox addressing
    envelopes.rs  signed-bundle wire format
  messaging/      inbound, sender, receiver, ratchet_store, room_keys,
                  attachments
  db/             schema, contacts, messages, rooms, identity
  security/       egress audit (lsof of own + i2pd subprocess)
  identity.rs     identity load / persist
  state.rs        AppState (vault runtime + i2p slots)
  commands.rs     Tauri IPC surface
  lib.rs          app entrypoint, tray, pre-warm task

src-tauri/tests/
  otpk_race.rs    one-time prekey zeroize + retransmission guards
  parser_fuzz.rs  envelope parser fuzzing (~85k inputs)
  ...

src/
  components/     layout, chat, contacts, rooms, vault, settings, shared
  hooks/          useCrypto, useKeyboard, useVault, useMessages
  stores/         appStore, conversationStore (Zustand)

scripts/
  bundle-i2pd.sh  prepares src-tauri/i2pd-bundle/ from Homebrew i2pd
  dev-dual.sh     launches two profile-isolated dev instances
  wipe-profile.sh resets a profile to first-launch state
  release.sh      builds + writes a populated Homebrew Cask file

homebrew/
  noctis-whisper.rb   source-of-truth Cask, copied into the tap repo
                      per release

docs/
  HOMEBREW.md     one-time tap setup + per-release flow

WHITEPAPER.md     architecture, threat model, cryptographic detail
LITEPAPER.md     condensed pitch + diagrams

Development

brew install i2pd                      # required by scripts/bundle-i2pd.sh
npm install
npm run tauri:dev                      # single instance (default profile)
./scripts/dev-dual.sh                  # two instances (default + alice)

Requirements:

• Rust 1.77+ (cargo)
• Node 22+ (npm)
• Xcode Command Line Tools
• Homebrew (for i2pd)

The dual-instance script kills any prior Whisper / orphan i2pd processes, pre-builds the debug binary, and sequentially launches both instances so they don't race on pick_free_port.

To reset a profile to first-launch state (testing onboarding / recovery-from-seed):

./scripts/wipe-profile.sh default     # one profile
./scripts/wipe-profile.sh --all       # default + alice + bob

Tests

cd src-tauri
cargo test --lib                                           # 104 unit tests
cargo test --test otpk_race                                # 3 integration
cargo test --test parser_fuzz --release                    # 4 fuzz, ~85k inputs
cargo test --lib --release                                 # 104 + tampering test

The release-only verify_i2pd_pin_catches_dylib_tampering test mutates a copy of the bundle and asserts the pin verification rejects both byte-tampered dylibs and tampered reseed certs by name.

CI runs all of the above on every push and pull request — see .github/workflows/ci.yml.

Releasing

See docs/HOMEBREW.md. Per release:

./scripts/release.sh

Outputs a built .dmg and a populated homebrew/noctis-whisper.rb ready to commit into your tap repo. Users install with one command — brew auto-taps from the fully-qualified cask reference:

brew install --cask jetp1ane/noctis-whisper/noctis-whisper

(The shorter brew install --cask noctis-whisper form will work after submission to homebrew/homebrew-cask clears review.)

Security disclosure

If you've found a vulnerability, please open a private security advisory on this repo rather than a public issue.

License

MIT — see LICENSE.