To password-protect your gallery, use your phone's built-in features like Google Photos' Locked Folder (Android) or Samsung's Secure Folder/Gallery Labs, or use a third-party app locker from the Play Store for a universal lock on the app itself, as methods vary by device.
Setting up a locked folder on Google Photos
You'll find a Locked folder option at the bottom. Once you tap on it, you'll be prompted to enter a password that is the same as your device password. On typing it, you can select the photos and videos you want to transfer to the locked folder.
You can also choose to turn on backup for Locked Folder at this time.
Lock an app
Go to the Home Screen. Locate the app you want to lock. Touch and hold the app icon until the quick actions menu opens. Tap Require Face ID (or Touch ID or Passcode).
Lock and unlock the Recently Deleted and Hidden collections
The Recently Deleted and Hidden collections are locked by default. You can unlock these collections using Face ID, Touch ID, or your passcode. To change the default setting from locked to unlocked, do the following: Go to the Settings app on your iPhone.
However, in most cases, you can find the picture password settings within the device's security or lock screen settings. Once you locate the option, you will be guided through the steps to choose an image and define the associated gestures. Follow the on-screen instructions to complete the setup.
Secret Photo Vault makes it easy, ensuring your files stay protected even when shared. Secure Lockscreen: Opt between a PIN or enable Face ID (or Touch ID) for quick and secure access to the app.
How to hide photos on iPhone or iPad. Open Photos. Tap and hold the photo or video that you want to hide. Tap Hide, then confirm that you want to hide the photo or video.
The difference between locking and hiding an app is that locking leaves the icon in view but guards its contents behind Face ID, Touch ID, or a passcode, whereas hiding removes the icon altogether and places the app itself into a hidden folder protected by Face ID.
To put a password on a folder or file, you can use your operating system's built-in features or a third-party tool like 7-Zip or VeraCrypt. While both Windows and macOS allow you to password protect your user account, this may not be enough to keep your most personal information secure.