Phone Recovery Key

Enroll your Android phone as a hardware-backed recovery key for your Sertone control center. If your identity is ever lost — disk failure, corrupted backup, container wipe — your phone restores it in under a minute.

How it works

Your Sertone control center has an identity: a cryptographic key that proves ownership of your wallet, your API registrations, and your earning history. This identity is stored encrypted on disk. If that file is lost, the control center enters recovery mode and cannot serve APIs until the identity is restored.

The Phone Recovery Key gives you a second copy of that identity, stored on your Android phone inside the hardware-backed Android Keystore — the same chip that protects your phone's payment credentials and fingerprints. Accessing the key always requires biometric authentication (fingerprint or face) or your device PIN.

Enrollment — one-time setup

1. Open the Sertone App on your phone.
2. Navigate to the Recovery tab.
3. Tap Enroll next to the control center you want to protect.
4. The app contacts your control center (you must be logged in) and retrieves the identity key.
5. Your phone stores the key in Android Keystore, protected by biometric.
6. Done. Your phone is now a recovery device. You can enroll multiple phones.

Recovery — restoring a lost identity

1. Open your control center's web console. If the identity is missing, you will see a Recovery Mode banner.
2. Click Generate Recovery QR. A QR code appears — valid for 30 minutes.
3. On your phone, open the Sertone App, go to the Recovery tab, and tap Restore a Control Center.
4. Scan the QR code with your phone's camera.
5. Authenticate with your biometric or PIN.
6. The app encrypts the recovery key using the session token from the QR code and sends it directly to your control center.
7. The control center decrypts it, restores the identity, and restarts. It is online again within a few seconds.

Security design

What is stored on the phone

The phone stores your control center's identity key — the root secret from which the wallet, API registration keys, and earning history are all derived. The file is stored as an encrypted item inside Android Keystore.

Android Keystore is a hardware-backed secure element available on Android 6.0 and above. The key is stored inside dedicated security hardware (the Trusted Execution Environment or a dedicated secure chip) and can only be accessed after biometric verification. It cannot be extracted by software, even on a rooted phone.

Transfer encryption

When you scan the QR code, the control center has generated a one-time 32-byte random session token. This token is the encryption key for the transfer:

1. The app reads your identity key from Android Keystore (biometric required).
2. The app encrypts the key with AES-256-GCM using the session token.
3. The encrypted payload is sent to your control center over HTTPS.
4. The control center decrypts it using the same token (which it generated and held in memory).
5. The session token is discarded immediately and cannot be reused.

The identity key is never visible in plaintext outside of your phone's hardware secure element and your control center's own memory.

What if my phone is stolen?

The identity key is locked behind biometric authentication. Without your fingerprint, face, or device PIN, the key cannot be read — not by software, and not by someone with physical access to the phone. The Sertone App does not store the key anywhere else.

Dual transport

The recovery QR contains your control center's URL. The phone connects directly to that URL — there is no relay server, no cloud service. If the URL in the QR is temporarily unreachable (for example, your IP changed), use your router's IP or update the URL in the app's settings.

Managing enrolled phones

View enrolled devices

In the web console, go to Settings › Recovery Devices. You will see a list of all phones currently enrolled, the date they were enrolled, and the last time each one was used.

Revoke a device

To remove a phone as a recovery device:

• From the web console: Go to Settings › Recovery Devices, find the device, and click Revoke.
• From the Sertone App: On the Recovery tab, tap Revoke next to the control center. This also deletes the key from your phone's Keystore.

What happens when I uninstall the app?

When you uninstall the Sertone App, Android Keystore automatically deletes all keys associated with the app. Your recovery key is gone from that phone. The control center still works — it does not depend on any phone. You should enroll another phone, or use a different backup method, before uninstalling.

Phone recovery is not your only backup

Sertone provides multiple layers of protection for your identity:

Frequently asked questions

Does Sertone ever see my recovery key?

No. The key is transferred directly from your phone to your control center over an encrypted connection. Sertone has no relay server in the path and no access to your data.

Can I enroll multiple phones?

Yes. There is no limit. Each enrolled phone gets a separate device entry in the control center. You can revoke individual phones independently.

Does this work if my control center is behind a firewall?

Yes, as long as your phone can reach the control center's IP on port 3002. If you are on the same local network, it works automatically. If you need remote access, configure port forwarding or use the VPN feature in the control center (Settings › VPN).

What Android version is required?

Android 6.0 (API 23) or newer. All Android phones manufactured after 2016 qualify.

Is there an iOS version?

An iOS version of the Sertone App is planned. Until then, use encrypted backup files or email backup as your primary recovery method on iOS.

The QR code expires. What if I miss the 30-minute window?

Close the QR modal in the web console and click Generate Recovery QR again. A fresh 30-minute session starts immediately.