> ## Documentation Index
> Fetch the complete documentation index at: https://gerfaut-wallet.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# App lock
> Lock Gerfaut behind a PIN or a password, unlock it with biometrics on Android, and hide it behind a working calculator on your launcher.
Lock Gerfaut so that someone at your unlocked phone or computer sees nothing of your wallets. Your wallet list stays encrypted whether the lock is on or off.
## Turn on the app lock
**1. Select the App lock switch**
Open **Settings** > **Security**. Gerfaut opens `Turn on the app lock`.
**2. Pick PIN or Password**
Select `PIN` (four to 12 digits) or `Password` (at least eight characters). Only a PIN opens the calculator disguise on Android.
**3. Enter the secret twice**
Enter `New PIN` or `New password`, then `Confirm`, and select **Turn on**. Gerfaut asks for the secret each time it opens.
**Android**
**Desktop**
## Lock and unlock
**Android**
Gerfaut asks for the secret each time you come back to it. Returning within ten minutes from a file picker, a save dialog or a share sheet that Gerfaut opened needs no secret. Select **Lock now** in **Settings** > **Security** to lock it by hand. While a lock is set, Android keeps Gerfaut out of screenshots and shows a blank card in the recent apps, or the calculator under the disguise.
A notification still names the wallet and gives the amount while a lock is set. To hide both, turn off [`Show wallet and amount`](/docs/settings/notifications#hide-the-wallet-and-amount-on-android).
**Desktop**
Press `Ctrl+L`, select **Lock** at the bottom of the sidebar, or select **Lock now** in **Settings** > **Security**. Otherwise Gerfaut stays unlocked until you close it.
On the `Locked` screen, enter the secret and select **Unlock**. After three wrong attempts, Gerfaut makes you wait five seconds, then doubles the wait at each failure, up to five minutes.
## Change or turn off the lock
Select **Change PIN** or **Change password** to replace the secret. Select the `App lock` switch again to turn the lock off. Both ask for the current secret.
## Unlock with biometrics on Android
**1. Select the Unlock with biometrics switch**
The switch shows when a fingerprint or a face is set up on the phone.
**2. Enter your PIN or password, then confirm the system prompt**
From then on, the lock screen opens the system prompt on its own. Select **Use fingerprint or face** to bring it back. Gerfaut never sees the biometric itself.
Only a biometric that Android rates as strong unlocks Gerfaut. Many face unlocks that use the front camera are rated weak, since a photo can fool them. On a phone with a weak one only, the switch stays greyed out and says why.
When the fingerprints or faces on the phone change, biometrics stop opening Gerfaut, so nobody can add their own finger to get in. Unlock with your PIN or password, then turn the switch on again in **Settings** > **Security**.
## Disguise the app as a calculator on Android
> [!WARNING]
>
> With the disguise on, the PIN is the only way into Gerfaut. If you forget it, only a [backup](#start-over-after-a-forgotten-pin-or-password) brings your wallets back.
**1. Select Disguise the app**
It needs an app lock of the `PIN` kind. The sheet lists what changes, starting with the launcher, which shows `Calculator` instead of Gerfaut.
**2. Select Turn on the disguise**
From Android 13, the recent apps keep no picture of Gerfaut while it is disguised. On an older Android, clear your recent apps once, because Android may keep an older Gerfaut thumbnail.
**3. Open Gerfaut from the calculator**
Type your PIN on the calculator and press `=`. A wrong PIN gives a number like any calculator, with no hint. After three wrong PINs, the right one also gives a number until the [wait](#lock-and-unlock) ends.
Turning the disguise on changes how Gerfaut tells you about transactions:
* **Notifications:** Gerfaut posts none, and clears the ones already in the notification shade.
* **Live:** If Live is on, Gerfaut turns it off and sets `Check for transactions` to `Every 15 min`. Background checks post nothing either.
* **Widgets:** Gerfaut removes its widgets from your home screen.
* **Notification history:** If you turned on Android's notification history, it still lists Gerfaut's earlier notifications under its name. Turn the history off in Android's notification settings to clear it.
In **Settings** > **Notifications**, `New transactions` shows off and every notification setting stays greyed out while the disguise is on. The line under the switch says why. Once you turn the disguise off, `New transactions` is back as you left it.
## Turn off the disguise
Select the `Disguise the app` switch again, or turn the app lock off. Gerfaut does not restore Live or the widgets on its own:
* **Live:** If you used [Live](/docs/settings/notifications#turn-on-notifications), select `Live` again under `Check for transactions` in **Settings** > **Notifications**.
* **Widgets:** The disguise removed them from your home screen. [Add each one again](/docs/settings/notifications#put-a-widget-on-your-android-home-screen).
## Start over after a forgotten PIN or password
Nobody can reset a forgotten PIN or password, since Gerfaut keeps no copy of it. Start Gerfaut again on an empty vault, then restore your last [backup](/docs/settings/backup-and-sync#restore-a-backup).
> [!NOTE]
>
> Only the wallets in your backup come back. Add any other wallet again from its descriptor, extended public key or address.
**Android**
**1. Uninstall Gerfaut**
In the Android settings, open the list of apps, select Gerfaut and uninstall it.
**2. Install Gerfaut again**
Follow [Install on Android](/docs/getting-started/install-android).
**3. Restore the backup**
Follow [Restore a backup](/docs/settings/backup-and-sync#restore-a-backup).
**Desktop**
**1. Close Gerfaut**
Close every Gerfaut window.
**2. Rename the Gerfaut data folder**
Rename `com.gerfautwallet.gerfaut`, for example to `com.gerfautwallet.gerfaut.old`. Gerfaut keeps it here:
* **Linux:** `~/.local/share/com.gerfautwallet.gerfaut`
* **macOS:** `~/Library/Application Support/com.gerfautwallet.gerfaut`
* **Windows:** `%APPDATA%\com.gerfautwallet.gerfaut`
**3. Open Gerfaut and restore the backup**
Gerfaut opens on an empty vault, with no lock. Follow [Restore a backup](/docs/settings/backup-and-sync#restore-a-backup).
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