Arca Arca

Own Your Passwords.
Zero Knowledge. Zero Compromise.

The offline-first password manager and built-in 2FA authenticator with client-side Argon2id encryption and zero cloud dependency.

View on GitHub
Arca Arca Interactive Vault

GitHub Production

256B Padded

https://github.com

Username / Identity
security@pixra.dev
Master-Wrapped Password
••••••••••••••••••••
Cipher: XChaCha20-Poly1305 HLC: 2026-11-05T03:28:00Z#01

Core Security Pillars

Engineered From First Principles

No Google login, no telemetry beacons, and zero host-page DOM injection. Interact with each architecture module below.

Zero-Knowledge Sync

100% offline by default. When you opt into cross-device sync, our self-hostable Rust Blind Relay stores only 256-byte padded XChaCha20-Poly1305 blobs and merges updates via Hybrid Logical Clock (HLC) CRDTs.

Desktop
Argon2id Vault
Blind Relay
256B Blob Verified
Android
HLC #0042
RFC 6238 TOTP

Built-in 2FA

Generate RFC 6238 6-digit and 8-digit TOTP codes with a live 30-second countdown ring and enroll 2FA QR codes offline straight from your active tab.

Live TOTP Token
492 817

WebAuthn & Biometrics

Unlock your vault in milliseconds using hardware-backed WebAuthn PRF on desktop or Secure Enclave / StrongBox on mobile, protected by strict 3-strike fallback.

StrongBox Keystore Ready · 3-Strike Guard Armed

100% Open Source & Anti-Clickjacking

Licensed under AGPL-3.0 with deterministic reproducible builds (SOURCE_DATE_EPOCH). Autofill verifies 5 DOM security invariants before populating any field.

1. Bounds ✓
2. Opacity ✓
3. Visible ✓
4. Z-Index ✓
5. Origin ✓

Simple 3-Step Workflow

How It Works

Click any step below to inspect the underlying local cryptographic operation.

Step 01 · Local Key Derivation Trace
KDF = Argon2id(password, salt_128b, m=65536 KiB, t=3, p=4) → Unwraps 256-bit Master DEK in RAM
0 Network Packets Sent
Arca Available for Chrome, Brave & Android (com.pixra.arca)

Ready to take back control of your credentials?

100% offline-first, audited open-source cryptography, zero subscriptions.

Architecture & Trust

Frequently Asked Questions

Arca is 100% offline-first. Your vault is created and encrypted locally on your device using Argon2id and XChaCha20-Poly1305 without requiring an email address, cloud account, or central server.
Every vault record is padded via ISO/IEC 7816-4 to fixed 256-byte blocks before encryption, hiding credential lengths. Changes are signed with your device's Ed25519 key and merged conflict-free via Hybrid Logical Clock (HLC) CRDTs.
Upon vault creation, Arca generates a 24-word recovery phrase offline. Because Pixra Labs never holds your keys, your 24-word phrase or encrypted local export is the sole mathematical mechanism to restore your vault.
Yes. Arca is licensed under GNU AGPL-3.0 with deterministic builds (SOURCE_DATE_EPOCH) so you can self-host the lightweight Rust relay in Docker and verify release binaries bit-for-bit.
Built with:
Rust
Blind Relay Core
React
Deterministic UI
WebCrypto
SubtleCrypto + WASM
AGPL-3.0
Audited Open Source