Do not compare lock screens; compare storage
A polished PIN screen proves that the interface checks a PIN. It does not prove that original files, thumbnails, filenames, notes, or databases are encrypted. Ask the vendor to explain what is stored, where it is stored, and what a copied app-data directory contains.
The buying questions
| Question | NullVault answer | What another app should document |
|---|---|---|
| Are file contents encrypted? | AES-256-GCM authenticated encryption | Algorithm, mode, and boundary |
| Are names and previews protected? | App-managed filenames, metadata, and previews are encrypted | Every plaintext artifact created |
| Does one unlock reveal all vaults? | No; a pattern addresses one vault | Vault/profile disclosure behavior |
| Is an account required? | No for local use | Account, analytics, and sync requirements |
| What recovers a forgotten secret? | Device-recovery phrase on the same device | Exact recovery authority |
| What survives device loss? | Portable encrypted backup with separate phrase | Backup scope and restore test |
Example: Two apps both show a four-digit PIN screen. App A leaves thumbnails in an ordinary cache; App B encrypts previews and content. The interfaces look similar, but the storage boundary is materially different. Verify documentation instead of inferring security from appearance.
Why separate patterns matter
Many products unlock one account and then show folders. NullVault uses each pattern as an address for a different vault, with no ordinary master switcher. This reduces what one disclosed credential reveals through the normal app flow.
Red flags in any vault claim
- “Military-grade” without a storage and key-management explanation.
- “Deleted forever” without separating logical deletion from physical flash behavior.
- “Invisible” without naming operating-system and forensic limits.
- Recovery that support can perform without explaining what authority support holds.
- Backup that is mentioned without a restore workflow.
- An interface lock while exported thumbnails remain unprotected.
Bottom line
NullVault is designed for people who want a documented, layered security model rather than only a gallery lock. Another app can still be a better fit if it has independently verified implementation, needed accessibility features, cross-device sync, or an established platform you value more.
Comparison reviewed: 28 August 2026.