Using Flipper Zero as a U2F/FIDO Security Key

The Flipper Zero can act as a FIDO U2F security key over USB, letting you use it for two-factor authentication on Google, GitHub, Dropbox, and other supported services.

Requirements

• Flipper Zero with official firmware or Momentum/Unleashed
• USB cable connected to computer
• A supported service (Google, GitHub, Facebook, Dropbox, etc.)

Enabling U2F on Flipper

Official firmware:

1. Connect Flipper via USB
2. Settings → USB → U2F
3. Flipper now appears as a USB security key

On Unleashed/Momentum:

• Available as an app in the Apps → Tools menu

Registering With a Service — Example: GitHub

1. GitHub → Settings → Security → Two-factor authentication
2. Add a security key
3. Follow prompts — GitHub asks you to touch your security key
4. Press the back button on Flipper when prompted (this acts as the "touch" confirmation)
5. Name the key and save

Using for Login

1. Login to your account normally (username + password)
2. When 2FA prompt appears, connect Flipper via USB
3. Enable U2F mode on Flipper
4. Browser prompts to touch security key
5. Press the back button on Flipper
6. Authentication completes

Limitations

• Each Flipper generates a unique key per service registration
• If you lose the Flipper, you need a backup authentication method
• NFC-based FIDO (passkeys via NFC) is different — this only does USB U2F
• Flipper doesn't support FIDO2/WebAuthn resident keys (newer standard)

Backup

Register at least 2 security keys (or keep backup codes) — if your Flipper dies and U2F is your only 2FA, you're locked out.