Are photo vault apps actually safe?
A lock screen and encryption are two different products, and a lot of apps sell the first while describing the second. You can tell which one you installed in about ten minutes.
Real encryption vs a folder hider
AlterVaultFolder hider
What is on the disk
File format at rest
Encrypted, your key
Ordinary JPEG
Thumbnails protected
✓
✕
Survives a forensic extraction
✓
✕
Who can read it
Safe from someone holding your phone
✓
✓
Safe from a computer with a cable
✓
✕
Safe from the company
✓
n/a
Tells you can check
No password reset
✓
✕
Needs full library access
No, uses the picker
Often
Works in airplane mode
✓
✓
Findings from Jonathan Zdziarski's teardown of Private Photo Vault, IOActive's review of iOS photo vaults, and the Cybernews report on the Photo Vault Firebase leak.
Three kinds of app, all called a vault
Folder hider
Photos are moved to a directory the gallery does not scan. Files stay as ordinary JPEGs with EXIF intact. The PIN protects the interface, not the data. This is the most common design in the category and the one that markets hardest on security.
Cloud vault with server-side keys
Encrypted in transit and at rest, but the company holds the key. Protects against a stolen phone. Not against the company, a subpoena, an insider, or a database breach.
On-device, key from your code
Each file unreadable without your code, including to the people who wrote the app. The price is real: no password reset, and no cloud copy if the phone goes in a river.
What researchers keep finding
The same result, repeated for a decade by people who take these apps apart.
- Zdziarski on Private Photo Vault
- Photos stored as ordinary files with no encryption, and a PIN that did not resist inspection.
- IOActive on iOS photo vaults
- The same pattern across several apps: poorly handled credentials and images sitting in plain sight in the app container.
- Cybernews on Photo Vault by Brain Craft
- An unsecured Firebase database leaked emails, folder and file names, private notes and plaintext passwords. No device compromise required.
- 2026 vendor testing
- A majority of popular vault apps still storing readable image files behind a PIN screen, EXIF timestamps and GPS intact. Treat rival-run comparisons with scepticism, then notice the independent research says the same thing.
Five tests you can run in ten minutes
No computer, no jailbreak, no technical knowledge. These work on any vault app, including this one.
- 01Ask for a password resetIf the app can email you back into your photos, the key is not derived from your code and the company can read your library. The single most diagnostic question in the category, and it takes thirty seconds.
- 02Check its permissionsA vault holding full photo library access can read every photo on the phone, not just the ones you gave it. The system picker exists so an app needs no standing access at all.
- 03Use it in airplane modeAdd a photo, open it, scroll. Then watch its data usage for a week. A local vault that moved hundreds of megabytes is not a local vault.
- 04Uninstall and reinstallWith a test photo, not your library. If photos come back without you restoring a backup file, they were on a server, which means a server can read them.
- 05Read the Data safety sectionSelf-reported, so not proof, but a declared upload of photos contradicts a listing promising everything stays on the device, and that contradiction is on the record.
How AlterVault scores on its own five
- Password reset
- There is none. The key comes from your code through Argon2id and wraps a master key in the Android Keystore, so nobody at AlterVault can open your library.
- Permissions
- The photo, video, camera, microphone, location and biometric permissions are all removed from the build. Files arrive through the system picker, so the app has no standing access to your gallery. Check it in app info in a minute.
- Network
- Your photos never touch it, and there is no analytics library in the app at all. The binary does hold the standard internet permission, because the one-time purchase is verified through the store.
- Uninstall
- The photos go with the app. There is no server copy, which is why the encrypted backup file exists.
- Encryption
- XChaCha20-Poly1305 in 32 KiB chunks, thumbnails included, with the chunk index bound into the authentication so chunks cannot be reordered or spliced.
- The one it fails
- The source is not published, so the cipher is our word rather than something you can read. The other four checks all run against the installed app.
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