Most apps protect your data. GeoLocker can hide that it exists.

Plenty of apps encrypt your files. The catch is that the lock is obvious: anyone holding your phone can see you have a vault and pressure you to open it. GeoLocker's hidden vaults take that pressure point away.

A hidden vault opens only with a secret place on the map and a passphrase. Both are mixed straight into the encryption key, so there's nothing stored to check a guess against. Enter the wrong spot or the wrong passphrase and you get the same blank result as a phone with nothing on it. There's no list of vaults, no count, and nothing on the device that hints any exist.

If you're ever forced to open the app, hand over a decoy vault full of harmless notes while your real vaults stay invisible. You can even arm a duress vault that wipes the others the moment it's opened. That's real plausible deniability, and it's free for everyone.

Why the passphrase is hard to crack: Argon2id

Someone who has your phone can still try to guess a hidden vault's passphrase. GeoLocker makes every guess expensive by deriving the key with Argon2id, the algorithm that won the Password Hashing Competition, is standardised as RFC 9106, and is the one OWASP recommends for password storage.

Argon2id is memory-hard: it deliberately needs a large amount of memory for each attempt, which blunts the GPU and ASIC rigs that tear through ordinary hashes. On GeoLocker that means even on-device guessing is slow, so a longer passphrase and a non-obvious spot are genuinely strong. We're honest about the flip side: a short passphrase at an obvious place can still be guessed. The strength is in your hands.

What it protects against, honestly

No overselling. Here's what each situation looks like, and where the limits are.

Situation	How GeoLocker helps	Honest limit
Lost or stolen phone	Everything is AES-256-GCM encrypted, stays on the device, and auto-locks when the app goes to the background.	Only a risk if the phone is already unlocked with a vault open.
Someone on your unlocked phone	Biometric vaults still need Face ID; hidden vaults need the exact spot and passphrase.	Someone watching over your shoulder as you open one.
Forced to unlock	Hand over a decoy. Real hidden vaults leave no trace, so "there's nothing here" is believable.	Biometrics can be compelled; a known spot and passphrase opens the real vault.
Forensic lab extraction	Hidden vaults are indistinguishable from random filler, so a routine image reveals nothing about them.	A short or obvious passphrase can still be ground down on the device (Argon2id slows this).
iCloud, backup or network	Nothing syncs or leaves the device. No servers, no accounts, no analytics.	Local-only by design.