How ShyVault keeps vaults private

Last updated October 19, 2026

ShyVault is built so that your files can only be opened with your pattern or your recovery phrase, and so that nothing on your iPhone or in iCloud says how many vaults you have or what's in them.

Your pattern is the key

When you draw a pattern, ShyVault turns it into a key with Argon2id, a deliberately slow function that uses 64 MB of memory for every attempt. It also mixes in a secret that only your iPhone's Secure Enclave can produce, so a copy of your iPhone's storage isn't enough to try patterns on another computer.

That key unwraps the vault's own master key. Every file and thumbnail is encrypted with AES-256-GCM in pieces, and a damaged or altered piece fails to open instead of showing wrong data.

No list of vaults

Where to find a vault is worked out from its pattern, and every file name is random. ShyVault keeps no list of vaults and shows no "wrong pattern" message: a pattern it hasn't seen simply opens a new, empty vault.

Recovery phrases

Each vault gets nine random words, or a phrase you choose of at least 32 characters. The phrase unwraps the same master key through an even slower Argon2id setting. Repeated wrong phrases are slowed down further.

Screens and screenshots

ShyVault draws its window so that screenshots and screen recordings show black, and it locks when the screen is being recorded or mirrored. It also locks as soon as it loses focus, and the app switcher shows a cover instead of your files.

iCloud backup

Files, the vault's index and its recovery slot are encrypted on your iPhone before upload, padded to set sizes and split into pieces with random-looking names. The backup is useless without the recovery phrase, and it doesn't reveal what your files are or their exact sizes. A vault that changed on another device is never overwritten by an older copy.

Shared vaults

A sharing code is 120 random bits, shown as twelve words or a link. Shared files are re-encrypted with a key that comes from the code, under new random names, so nothing links them to your own vault. The list of shared files is signed by your device, and people who join refuse any list your device didn't sign.

Duress vaults

A duress vault's pattern opens it normally and removes the other vaults' patterns from that iPhone. Their files stay encrypted, and each comes back only with its recovery phrase.

What ShyVault can't protect against

• Someone who copies your iPhone's storage can see that encrypted vault files exist and roughly how many there are, though not open them.
• Anyone with a vault's recovery phrase or pattern can open it, and anyone with a sharing code can open that shared vault.
• Malware on a compromised iPhone, or someone watching your screen while a vault is open, can see what you see.
• If you forget a pattern and lose its recovery phrase, nobody can open that vault, including us.

Report a security problem

If you find a vulnerability, please email support@shyvault.app with "Security" in the subject. We'll reply, keep you updated while we fix it, and credit you if you'd like.