Security
How the vault actually works
For an app like this, the security explanation is the product description. Here is the whole design, in plain language — and every claim below is checkable against how the app behaves.
- Cipher
- AES-256-GCM (authenticated)
- Key size
- 256-bit, generated on device
- Key storage
- iOS Keychain, this device only
- Passcode hashing
- PBKDF2-HMAC-SHA256, 100,000 iterations
- Server
- None
- Account
- None
Encryption
Every file you add is encrypted with AES-256 in GCM mode before it is written to disk, using Apple's CryptoKit. GCM is authenticated encryption: as well as making the file unreadable, it detects tampering, so a modified file fails to open rather than decrypting into something wrong.
Large files are encrypted in 5 MB chunks rather than loaded whole, so a long video does not need to fit in memory to be protected.
The cryptography is deliberately unoriginal. Standard, audited primitives from the platform vendor are the correct choice here — home-grown encryption is the single most common way apps in this category fail.
Where the key lives
The 256-bit vault key is generated on your device and stored in the iOS Keychain, never in the vault itself and never in a file you could copy somewhere by accident.
It is stored with the accessibility class
kSecAttrAccessibleWhenUnlockedThisDeviceOnly. Two things follow from that, and
they are the important ones:
- This device only — the key never syncs to iCloud Keychain, so it exists in exactly one place.
- When unlocked — it is not readable while the phone is locked, even by LockBox.
Your passcode is never stored, in any form that could be reversed. It is hashed with PBKDF2-HMAC-SHA256 over 100,000 iterations with a per-vault random salt — the iteration count is what makes guessing expensive.
Why vault data is kept out of iCloud backups
Vault files are explicitly flagged as excluded from backup. The reasoning: a backup is a second copy in a place you did not individually choose, and the entire point of this app is that you know where your private files are.
This has a real consequence, so it is worth stating bluntly:
if you delete LockBox, or lose the phone, the vault goes with it.
Use Settings → Export Backup before switching or reinstalling. The export is a
single encrypted .lockbox file sealed with a password you choose — you decide
where it lives.
What is not there
The absences do more work than the features:
- No server. Not "we don't look at your files" — there is no service holding them.
- No account. No email, no sign-in, nothing that ties a vault to a person.
- No analytics on your content. Nothing about what is in your vault is measured or transmitted.
- No ads, no ad identifiers, no third-party SDKs reading your library.
Payments go through Apple, so we never see card details either. The full text is in the privacy policy.
Honest limits
No security design is unconditional, and a vault app that implies otherwise is selling something. What LockBox does not protect against:
- A forgotten passcode. There is no back door, because a back door for you is a back door for anyone holding your phone. LockBox does offer an optional recovery passphrase, which protects against the rare case of the Keychain entry being lost — it is not a way to get in without knowing something.
- A compromised device. If iOS itself is compromised, or someone has your device passcode and your vault passcode, encryption at rest cannot help.
- A backup password you lose. An exported
.lockboxfile cannot be recovered without its password. We cannot reset it. - Screenshots and exports you make yourself. Once a file leaves the vault, it is an ordinary file again.
Questions people ask
Could Viya App Studio decrypt my vault if asked?
No. We never receive the key or the files, because there is no server that could receive them. There is nothing for us to hand over.
What if my phone is unlocked and taken from me?
The vault still needs its own passcode or biometric. Add a decoy passcode and a per-album PIN if you expect to be asked to open the app.
Is the encryption something you invented?
No, and that matters. LockBox uses Apple’s CryptoKit implementation of AES-256-GCM — a standard, audited primitive. Home-grown cryptography is how vault apps fail.
What is actually in the exported backup?
A single .lockbox file containing your encrypted media and its index, sealed with a password you choose. It is opaque to us and to anyone who does not have that password.
Read it, then judge it
If something here is unclear or looks wrong, tell us — hello@viyaappstudio.com. Being checkable is the point.