Arca vs Calculator vault apps
Calculator-style hider apps disguise themselves as a working calculator and reveal a hidden gallery when you type a secret code. The disguise can be clever, but it's mostly security-by-obscurity: the encryption underneath varies enormously, and many store files with weak or no protection.
“Calculator vault” refers to a category of apps, not one product. Quality varies widely — always verify a specific app's encryption.
Obscurity is not cryptography
A calculator disguise solves exactly one problem: someone glancing at your home screen won't know you have a vault. It does nothing once the app is opened or the device is examined. What protects the files themselves is the encryption underneath, and in this category that layer is wildly inconsistent — some apps use real encryption, many simply move files into a hidden folder, and most document nothing at all.
That inconsistency is the real risk. Because “calculator vault” is a category of look-alike apps rather than one product, two apps with identical icons can differ completely in what happens to your photos — including whether they quietly upload them to an ad-supported cloud.
Which one should you choose?
If all you need is casual concealment — keeping a nosy friend from stumbling onto an album — a disguise app may be enough, provided you verify what it actually does with your files before trusting it.
If you need your photos to stay unreadable when someone has your phone, your passcode, and time — a breakup, a border crossing, a stolen device — you need documented encryption, not a costume. Arca states its design plainly: AES-256-GCM per file, an Argon2id-derived key, and local vault storage. And if deniability matters, the decoy vault gives you a second PIN that opens a harmless vault — real encryption underneath, disguise on top rather than instead.
Switching to Arca
First, get your photos out of the disguise app and back into the Photos app — check the export is lossless, since some of these apps recompress or trap files behind a paywall. Then import into Arca and confirm your photos open. Finish by deleting the originals from the old app and from Photos, including Recently Deleted.
Then create an .arcavault backup on a computer or drive you control. Your photos are now protected by cryptography you can name, with an export path that will always be there.
Where Arca stands
Arca can wear a disguise too — its optional Calculator Lock Screen works as a real calculator until you enter your PIN and tap = — but it doesn't rely on one. What protects your photos is cryptography you can describe: AES-256-GCM per file, an Argon2id-derived key, and local vault storage. The disguise and the decoy vault sit on top of real encryption, not instead of it.
Questions
Are calculator vault apps safe? +
The calculator disguise hides the app's purpose, but it doesn't encrypt anything by itself. Safety depends entirely on the underlying encryption, which is often weak or undocumented. Check for real, described encryption.
Does Arca have a disguise mode? +
Yes. Turn on Calculator Lock Screen and the locked app works like a calculator: enter your 6-digit PIN and tap = to unlock. A Phone Lock Screen option does the same with the phone keypad, and alternate icons include Calculator and Calendar styles. Unlike many calculator vaults, the disguise sits on top of AES-256 encryption.
How can I tell if a vault app really encrypts my photos? +
Look for specifics: a named algorithm (like AES-256), a described key derivation (how your PIN becomes a key), a clear statement of whether files stay on-device or go to a cloud, and a documented export path. If an app names none of these, assume it only hides files.
What is a decoy vault for? +
For moments when you're pressured to unlock — a second PIN opens a separate, harmless vault instead of your real one. In Arca this deniability sits on top of real per-file encryption, so it's an extra layer rather than the only protection.
Your photos. Truly private.
Keep your photos in an encrypted vault on your iPhone or Android phone, with no Arca account or automatic vault upload.
Free to download · iPhone with iOS 18+ · Android 9+