Encrypts files with XChaCha20-Poly1305 before they touch your device storage, protecting thumbnails and filenames as well as originals. Altervault: Hidden Photo Vault, from Devaprime, targets privacy-minded Android users in the photography category, offering local-only storage and offline operation. It pairs Argon2id key derivation with PIN and emoji access codes, includes a decoy gallery and shake-to-hide action, and aims to keep sensitive media under your control without cloud accounts or tracking.

What the app protects and the threat model it assumes

You store photos, videos, and documents inside an encrypted container that the app writes to local storage, and every file uses XChaCha20-Poly1305 encryption before being saved. The developer implements a zero-knowledge architecture so Devaprime has no access to your keys or data. That model means the app defends against someone who gains access to the device filesystem, because filenames and thumbnails are encrypted alongside the content.

How you open, hide, and recover your vault

Access is controlled with PINs or an emoji-based code, and the app offers a decoy gallery that opens with a different code to present harmless content. You can trigger a quick conceal action by shaking the device to swap to the decoy view. During setup the tool provides a twelve-word recovery phrase you can use to regain access if you forget your code; the developer cannot reset codes for you.

Backup, portability, and workflow for exporting media

The vault supports an encrypted backup that exports as a single .vault file you can move to another device and restore with the original access code. You can also export items individually or in bulk at original quality. Because storage and backups remain local or device-to-device, the app avoids account-based syncing and any internet dependency for normal operation.

Good gateway for users who demand offline control, with one clear trade-off

If you need an offline, account-free way to keep private media under your control, Altervault fits that need by keeping everything local and encrypted. The trade-off is responsibility for recovery: losing your recovery phrase or code means you cannot rely on the developer to restore access. For privacy-conscious individuals who accept that responsibility, the app offers a focused, secure entry point to private storage.