Help & FAQ

Any YubiKey that supports HMAC-SHA1 challenge-response works with Yubi AppGate. This includes the YubiKey 5 series (5 NFC, 5C, 5C NFC, 5Ci, 5C Nano), the YubiKey 5 FIPS series, and older YubiKey 4 models. The key must have an HMAC-SHA1 secret programmed in Slot 1 or Slot 2 using YubiKey Manager (ykman) or the YubiKey Personalization Tool.

1. Install YubiKey Manager on your computer.
2. Insert your YubiKey and open YubiKey Manager.
3. Navigate to Applications → OTP.
4. Select a slot (Slot 1 or Slot 2) and choose Challenge-Response.
5. Select HMAC-SHA1 and either generate a secret or enter your own 20-byte hex secret.
6. Click Finish.

Then enroll the same slot in the Yubi AppGate app by tapping or connecting your YubiKey.

• Make sure NFC is enabled in your phone's Settings.
• Hold the YubiKey flat against the back of your phone, near the NFC antenna (usually upper-center).
• Keep the key steady for 1 to 2 seconds. Don't tap and pull away too quickly.
• Remove any thick phone case that might block NFC signals.
• Check the transport status in the app's Setup tab to confirm NFC shows "Ready."

• Ensure your phone supports USB OTG (On-The-Go).
• Plug the YubiKey directly into the USB-C port (not through a hub).
• If prompted for USB permission, tap Allow.
• Make sure CCID mode is enabled on your YubiKey (it is by default). You can verify via YubiKey Manager under Interfaces.

This means the YubiKey's HMAC-SHA1 response doesn't match the enrolled identity. Common causes:

• Wrong slot selected: Make sure the slot in the app matches the slot where you programmed the HMAC-SHA1 secret.
• Secret was re-programmed: If you reprogrammed the YubiKey's secret after enrollment, you need to reset enrollment in the app and re-enroll.
• Different YubiKey: You're tapping a different YubiKey than the one originally enrolled.

To fix: go to Setup → Reset enrollment, then re-enroll with the correct YubiKey and slot.

Go to Setup and tap Open Accessibility Settings. Find Yubi AppGate in the list and enable it. Once active, any protected app will show the lock screen no matter how it's opened (home screen, recent apps, deep links, etc.).

In the Setup tab, tap Enable Uninstall Protection. This activates device administrator mode, which requires your phone's screen lock to deactivate before the app can be uninstalled.

The free version lets you protect up to 2 apps. Upgrade to Pro for unlimited app locks.

No. Yubi AppGate operates entirely offline. No internet connection is needed for enrollment or authentication. The app has no network permissions beyond what the Play Store requires for license verification.