SecretVault

A browser-based tool for encrypting and splitting secret keys.
Runs entirely locally — no server, no cloud, no data transmission.

Live: sv.mangolila.at

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Concept

A secret key (API token, password, seed phrase, …) is encrypted with a password and then split into two halves:

• Part 1 → store on a website, in a repo, or on a server
• Part 2 → keep yourself (text or QR code)
• Password → memorize it

All three components together are required to recover the original key. None of the three parts alone is sufficient.

Crypto Stack

Component	Detail
Encryption	AES-256-GCM (including integrity check)
Key derivation	PBKDF2-SHA256, 250,000 iterations, 16-byte salt
IV/Nonce	12 bytes, randomly generated per encryption
Secret splitting	Interleaving — even indices → Part 1, odd → Part 2
Implementation	Web Crypto API (browser-native)

Encrypted blob binary format: [Salt 16B][IV 12B][AES-GCM Ciphertext + 16B Tag] → Base64

Development

make install       # Install dependencies
make dev           # Dev server → http://localhost:5173
make test          # Run tests once
make test-watch    # Run tests in watch mode
make build         # Production build → dist/
make clean         # Delete node_modules + dist/

Deploy

make deploy                              # Build + rsync with default config
make deploy DEPLOY_HOST=user@server      # Specify a different host

Defaults in Makefile:

DEPLOY_HOST = deploy@mangolila.at
DEPLOY_PATH = /var/www/sv.mangolila.at

Nginx config: nginx/sv.mangolila.at.conf

Project Structure

src/
  App.tsx              ← Root component, routing, language state
  LandingPage.tsx      ← Landing page (hero, use cases, security, CTA)
  SecretVault.tsx      ← Encryption app
  i18n.ts              ← Translations DE / EN
  theme.ts             ← Color constants
  constants.ts         ← Shared constants (MAX_LEN)
  main.tsx             ← React entry point
  __tests__/
    setup.ts           ← Vitest/jsdom mocks
    SecretVault.test.tsx
nginx/
  sv.mangolila.at.conf ← Nginx config for the subdomain
index.html
package.json
vite.config.ts
Makefile

Tech Stack

Framework	React 18
Build	Vite
Language	TypeScript
Tests	Vitest + jsdom + Testing Library
i18n	Custom solution (no external package)
Crypto	Web Crypto API (browser-native, no npm package)
QR Code	qrcode