It depends on the app. Apple says iCloud Backup includes data from the apps on your iPhone, so a vault app’s files can end up there. Vault9 keeps its vault out of that backup and makes its own encrypted copy in your iCloud storage, the iCloud backup.
What Apple’s backup and its encryption mean for a vault
Apple lists data from installed apps as part of iCloud Backup. Photos in your Photos library follow another rule: with iCloud Photos on they sync and stay out of the backup, and with it off the backup may include them. Photos inside a vault app are not in that library.
Apple says iCloud Backup is encrypted in transit and at rest. By default Apple holds the keys, and can help you recover your data if you can sign in to your Apple Account. With Advanced Data Protection, only your trusted devices hold the keys, and Apple cannot help you if you lose access. Then you need a device passcode, a recovery contact or a recovery key.
What Vault9 saves, and what stays on the iPhone
The iCloud backup is the only copy of the vault outside the iPhone. The app saves it while it is open, and goes on in the background for as long as iOS allows. It is a backup, not sync between devices, and only one iPhone, the active iPhone, saves to it. The vault is not in your normal iPhone backup (iCloud or computer).
The Secret Key is the part that does not travel. The phone makes this random key when you create the vault, and it stays in the iPhone Keychain, set to “this device only”. To open the vault you need the Secret Key and your pattern or passphrase (or Face ID, if you turn it on).
So on a new iPhone you need 3 things: the iCloud backup, the Secret Key from your Emergency Kit, and your pattern or passphrase. How to move the vault to a new iPhone lists the steps.
Four limits of the iCloud backup
- Apple can see that it exists, the number of items, their padded sizes, the dates of changes and the model of the active iPhone. If you lose access to your Apple Account, you lose the backup.
- After you change your pattern or passphrase, the backup opens with the old one until the change is saved.
- Deleting the vault on the active iPhone also deletes the backup, and that needs a working iCloud connection. You can also delete the backup in Settings.
- An item that is not in the backup is gone if you lose the phone. The app shows the progress and the reason for an error, for example full iCloud storage, so look at it before you trust the backup.
Sources
- Apple Support: What does iCloud back up? (checked 2026-11-06)
- Apple Support: iCloud data security overview (checked 2026-11-06)
