Open-source browser extension for PGP encryption, decryption, and signing.
Built with Rust/WebAssembly. Private keys never touch the JS heap unless they have to.
Open source and transparent. Most PGP browser extensions are closed source. You shouldn't trust a black box with your secrets.
Crypto runs in WASM, not JavaScript. All PGP operations run in a Rust/Sequoia-PGP WebAssembly sandbox. JS holds only an opaque integer handle to your key - the actual bytes live in WASM linear memory and are zeroized on drop. Private keys briefly pass through JS during generation and import before being encrypted and stored.
Passkey unlock. Protect keys with WebAuthn PRF - unlock with Touch ID, Face ID, Windows Hello, or a YubiKey instead of a password. The PRF output is combined with a stored secret via HKDF-SHA256, and the entire unlock flow runs in WASM.
Argon2id for passwords. 64 MB memory, 3 iterations - GPU brute-force resistant. The KDF, decryption, and key storage all happen in WASM. Password bytes are zeroed on both sides immediately after use.
Atomic decrypt + verify. Plaintext and signature result are returned together in a single packed response. Bad signature = no plaintext returned. No TOCTOU window.
Zeroization everywhere. zeroize crate on all stored keys and intermediates (Rust). Uint8Array.fill(0) on passwords, PRF outputs, and derived keys (JS). WASM memory isn't GC'd, so zeroization is deterministic.
Per-key AAD. Each private key is encrypted with AES-256-GCM using Additional Authenticated Data bound to its fingerprint. Swapping blobs between key slots fails.
- ECC (Cv25519) or RSA-4096 key generation
- Encrypt to multiple recipients, with optional signing
- Decrypt with automatic signature verification
- Cleartext sign and verify
- Import/export armored keys
- One-file backup: export/import all keys and contacts (passphrase-encrypted by default)
- Sign & verify Chrome extension packages (
.crx) for the Web Store's Verified CRX Uploads (optional; off by default) - Right-click context menu on selected text
- Auto-lock on inactivity, panel close, or per-operation (never-cache mode)
- Optional Chrome sync or local-only storage
| Layer | Mechanism |
|---|---|
| Crypto engine | Sequoia-PGP in WASM (keys in JS only during gen/import) |
| Key unlock | WebAuthn PRF (passkeys) or Argon2id 64 MB (passwords) |
| Key storage | AES-256-GCM with per-key AAD |
| Memory | zeroize crate (Rust) + manual zeroing (JS) |
| Signatures | Atomic decrypt+verify (no TOCTOU) |
| Sessions | Auto-lock on inactivity, panel close, or per-op |
| Brute-force | Argon2id 64 MB / 3 iterations - the cost sits in the KDF, which also holds against an offline attack on a stolen blob |
| Scope | No content scripts - extension sandbox only |
- PGP: Rust / Sequoia-PGP / WebAssembly
- Extension: WXT + React + Tailwind
- Key protection: WebAuthn PRF or Argon2id + AES-256-GCM
- UI: shadcn/ui
pnpm install
pnpm dev # dev server with hot reload
pnpm test # unit tests (vitest); Rust engine tests: cargo test in apps/pgp/gpg-wasm
pnpm build # production build (builds WASM automatically)
pnpm zip # package for Chrome Web Store / Firefox Add-onsThe WASM module must be built from source. To rebuild manually:
cd apps/pgp && pnpm build:wasmapps/pgp/ Extension source
components/ React UI
entrypoints/ background + sidepanel
hooks/ keyring, sessions, contacts
lib/pgp/ WASM wrapper + operations
lib/protection/ WebAuthn PRF, Argon2id, AES-256-GCM
lib/storage/ chrome.storage with mutex
gpg-wasm/ Rust/WASM engine (sequoia-openpgp)
packages/ui/ shadcn/ui components
tooling/ eslint, prettier, tailwind, tsconfig
Built with significant AI assistance (Claude). UI, React plumbing, storage, and extension wiring were largely AI-generated.
The cryptographic implementations - Rust/WASM engine, key protection, WebAuthn PRF, Argon2id configuration - were human-designed and human-reviewed. We don't trust vibes-based crypto.
MIT