Your complete password vault — passwords, notes and 2FA secrets — lives encrypted inside an ordinary-looking PNG file. Larger files use separate encrypted containers. Here is what happens during setup and every unlock.
First-time setup takes about two minutes. After that, every time you open BlindLock you wait about ten seconds for the PIN check. It feels slow, and that is the point: if someone later tries to guess your PIN — for example after stealing your device — every wrong attempt costs those same ten seconds. Without that brake, a program could try thousands of PINs in a few minutes. With it, the same attack takes days or weeks and is not worth the effort. The PIN only opens BlindLock on your device. It does not open your vault. The vault key depends on your device's security chip and a release from the BlindLock licence server, and to sign you in BlindLock also asks for your master password.
Pick a PNG file on your device with at least 4.4 megapixels, about 2100 × 2100 pixels. BlindLock inspects the carrier's capacity and confirms it can hold the payload without visible distortion.
The carrier stays exactly where you put it.
You set your master password, and BlindLock binds its security anchor to your device's protected hardware — TPM 2.0 or Secure Enclave, depending on the platform. You can also set up a hardware key such as a YubiKey, Google Titan or SoloKey.
The key to your login image depends on your device's security chip and on a release from the BlindLock licence server. To sign you in, BlindLock also asks for your master password. The same file yields no usable key on another computer.
Passwords, TOTP seeds and notes are encrypted in memory before being written into the carrier. Larger documents and media go into separate encrypted file-vault containers, so the two storage types remain distinct. The login image uses classical 256-bit dual AEAD. File-vault containers use authenticated encryption as documented on the Security page.
BlindLock stores your encrypted password vault invisibly inside the image you chose. Visually nothing changes: before and after, the file looks the same. You cannot tell from looking at the image that data is hidden inside it.
Keep the active carrier safe and back it up deliberately. For migration and emergencies, also create an encrypted BlindLock backup and keep its twelve words separately. If you use file vaults, also back up each vault file. BlindLock stores the rescue for every file vault in your backup file by itself. You may choose local media, an external drive or a cloud-synchronised folder. BlindLock does not operate a central backup service.
Every unlock follows the same local cryptographic path. Activation and each new unlock also need a brief encrypted connection. Only technical data is exchanged: licence, device, platform and version details, and the server returns a 32-byte value that goes into your vault key. No vault contents are sent. Once unlocked, the vault continues to work locally until the session closes.
The key to your login image is formed fresh on every unlock, bound to exactly this image:
If the security chip or the release is missing, no key comes about at all. The vault stays closed.
Large documents and media live in separate encrypted file vaults.
Four places, four different things.
Passwords, notes and 2FA secrets are sealed twice before they ever reach the image: AES-256-GCM and XChaCha20-Poly1305 stacked, with independent keys. Breaking one seal still leaves the other.
The data goes into the pixels themselves, a tiny fraction per pixel — far too little for an eye to catch. The method is called F5 matrix encoding. Its trick: it spreads the data so that out of seven positions it could use, at most one has to be changed. And the less that changes, the less the image differs from an untouched photo — including for the tools built to look for exactly that.
Which positions are used is decided by a random key that your device's security chip keeps sealed. Without that key nobody knows where to look. And there is no obvious BlindLock marker in the file.
The key to your vault is stored nowhere — not with you, not on the BlindLock server. It is assembled fresh every time you open, from the key part of your security chip and a release from the licence server, bound to exactly this image. The release is a random number that means nothing on its own. Your machine fetches it fresh from the BlindLock server every time you open. BlindLock also asks for your PIN and your master password.
If the security chip or the release is missing, no key comes about at all. The vault stays closed.
Only technical data is exchanged: licence, device, platform and version details, and the server returns a 32-byte value that goes into your vault key. What your vault holds, the BlindLock server never learns — that never leaves your computer.
And if the BlindLock server is unreachable, that does not lock you out. At your last unlock it gave your device a signed pass, kept sealed by the security chip and good for seven days. For that long BlindLock opens without internet too.
Files live in separate encrypted containers with ChaCha20-Poly1305, hardware-sealed to your computer's security chip. Argon2id derives the key itself from the vault password, with at least 512 MiB. You set how large a container is when you create it.
Honest answers to the awkward cases.
BlindLock cannot reset it. You still get your entries back: create a new login image with a new master password and restore your entries into it from your backup file with your twelve words. Changes after your last backup are not included.
Without the security chip of the old device, the carrier yields no usable key, not even with your master password. Restore your encrypted backup on the new device — with the backup file and the separately stored twelve words. Then sign in with your master password as usual.
As long as you can still sign in on your device, nothing is lost: reveal your twelve words again under Backup and write them down anew. If you would rather retire them, generate twelve new ones there. The old words lose all effect at once, and BlindLock writes you a fresh backup file — the old ones no longer fit.
A copied carrier file alone is not enough. Without your device's security chip and the licence server's release, no usable key comes about. On top of that, BlindLock asks for your PIN, your master password and, if enabled, your hardware key.
Cloudless storage, privacy, hardware binding and steganography — then compare honestly.
Open the interactive demo with the real desktop flow — or check Lifetime pricing for later.