Kripta

A self-hosted, zero-knowledge, multi-user 2FA/TOTP authenticator. The Google Authenticator replacement that you own and control. Every OTP secret is encrypted on your device before it ever reaches the server.

Overview

Kripta is a private vault for your two-factor authentication codes. Add accounts by scanning a QR code, uploading a QR image, or entering the secret manually, then generate TOTP and HOTP codes on any device you sign in from.

Unlike most authenticators, Kripta is zero-knowledge: your master password, encryption keys, and OTP secrets never leave the browser in plaintext. The server only ever stores hashes and ciphertext, so even a compromised server, or a curious administrator, cannot read your codes.

Why Kripta

Most authenticators either lock your secrets to a single device or hand your data to a third-party cloud. Kripta gives you both convenience and control:

• Zero-knowledge by design. Secrets are encrypted client-side with a key derived from your password. The server sees only ciphertext.
• Self-hosted. Run it on your own infrastructure with Docker and PostgreSQL.
• Multi-user. One installation for your whole team, with invite-based provisioning and role-based access.
• Synced across devices. Open the same vault from anywhere by signing in. No manual export or import.

Features

• Flexible entry. Add accounts via QR scan (camera), QR image upload, or manual input. Supports TOTP and HOTP, SHA-1/256/512, 6 to 8 digits, and custom periods.
• Fast day-to-day use. Real-time codes with a countdown ring, one-click copy, drag-to-reorder, and a command palette (Cmd/Ctrl + K) for instant search and copy.
• First-run setup wizard. Create the superadmin account the first time you deploy.
• Invitations. Add users with optional email pinning, User or Superadmin roles, and link expiry.
• Mandatory recovery codes. The only way to recover access if you forget your password. The server cannot reset it for you.
• Admin dashboard. Manage users, invitations, and a full audit log.
• Account management. Change your password without re-encrypting items, review and revoke active sessions.
• Polished UI. English and Bahasa Indonesia, light and dark themes, responsive layout (desktop sidebar, mobile bottom navigation).

Screenshots

Vault (light)	Command palette
Settings and language	Admin audit log

Security model

Kripta uses a Bitwarden-style key hierarchy, derived entirely on the client:

flowchart TD
    PW["Master password"] -->|"Argon2id + salt"| MK["masterKey"]
    MK -->|"HKDF"| SK["stretchedKey"]
    MK -->|"SHA-256"| AH["authHash"]
    RC["Recovery code"] -->|"HKDF"| RK["recoveryKey"]

    VK(["vaultKey (random 32 bytes)"])
    SK -->|"AES-GCM wrap"| PVK["protectedVaultKey"]
    VK --> PVK
    RK -->|"AES-GCM wrap"| PVKR["protectedVaultKeyByRecovery"]
    VK --> PVKR
    VK -->|"AES-GCM, per item"| CT["OTP ciphertext"]
    AH --> AHH["Argon2id(authHash)"]

    subgraph SERVER["Stored on the server: ciphertext and hashes only"]
        AHH
        PVK
        PVKR
        CT
    end

Loading

What the server stores: Argon2id(authHash), Argon2id(recoveryAuthHash), KDF salt and parameters (public), protectedVaultKey, protectedVaultKeyByRecovery, and item ciphertext. It never stores passwords, secrets, or keys in plaintext.

Additional hardening:

• Database-backed sessions that can be revoked, with httpOnly + Secure + SameSite=Strict cookies and idle plus absolute timeouts.
• CSRF protection with a session-bound double-submit token, plus origin checks.
• Rate limiting and exponential account lockout on login, invites, and recovery, with user-enumeration mitigation at prelogin.
• Strict security headers including a nonce-based Content Security Policy, HSTS, X-Frame-Options, X-Content-Type-Options, and Referrer-Policy.
• Argon2id for server hashing and client KDF (at least 64 MiB memory), zod input validation, ownership checks on every endpoint, and an audit log that never records secrets.

Accepted trade-off: codes are generated only in the browser, and forgetting your password without a recovery code means the data is permanently lost. That is the price of true zero-knowledge.

Quick start (Docker)

Prerequisites: Docker and Docker Compose.

git clone https://github.com/idhin/kripta.git
cd kripta

# Create the .env file used by docker compose (change the password!)
cat > .env <<'EOF'
POSTGRES_USER=kripta
POSTGRES_PASSWORD=change-this-to-a-strong-password
POSTGRES_DB=kripta
APP_URL=http://localhost:28347
AUTH_COOKIE_SECURE=false
APP_PORT=28347
EOF

docker compose up -d --build

Open http://localhost:28347. You will be redirected to /install to create the superadmin. Save the recovery code that is shown.

The default host port is intentionally uncommon (28347) so it will not clash with other services on your server. Change APP_PORT (and APP_URL to match) to anything you like. The containers are named kripta-app and kripta-db.

Production: put Kripta behind an HTTPS reverse proxy (Caddy, Nginx, or Traefik), then set APP_URL=https://your-domain and AUTH_COOKIE_SECURE=true.

Local development

Prerequisites: Node 20+, and PostgreSQL (or the docker run command below).

npm install

# Run a local Postgres
docker run -d --name kripta-pg \
  -e POSTGRES_USER=kripta -e POSTGRES_PASSWORD=kripta -e POSTGRES_DB=kripta \
  -p 5432:5432 postgres:16-alpine

cp .env.example .env         # adjust DATABASE_URL if needed
npm run db:migrate           # apply migrations
npm run dev                  # http://localhost:3000

Useful scripts: npm run db:studio (Prisma Studio), npm run db:deploy (production migrations), npm run build && npm start.

Configuration

Variable	Description	Default
DATABASE_URL	PostgreSQL connection string	postgresql://kripta:kripta@localhost:5432/kripta?schema=public
APP_URL	Public app URL, used for origin checks and invite links	http://localhost:3000
AUTH_COOKIE_SECURE	Set to true only when served over HTTPS	false
SESSION_ABSOLUTE_TTL	Absolute session lifetime, in seconds	2592000 (30 days)
SESSION_IDLE_TTL	Idle session lifetime, in seconds	43200 (12 hours)
APP_PORT	Host port published by Docker Compose (container listens on 3000)	28347

Backup

Just back up the database. It only contains ciphertext and hashes:

docker compose exec db pg_dump -U kripta kripta > kripta-backup.sql

Tech stack

Next.js 14 (App Router), React, TypeScript, Tailwind CSS, Zustand, Prisma, PostgreSQL, @node-rs/argon2 (server), hash-wasm and Web Crypto (client), otpauth, qr-scanner, and zod.

Contributing

Issues and pull requests are welcome. If you find a security concern, please open a private report rather than a public issue.

License

MIT © Khulafaur Rasyidin. See LICENSE.