How PrivyDeck vault encryption works

Encryption happens in your browser first

When you add a file, PrivyDeck derives a key from your vault passphrase in the browser (Web Crypto) and encrypts the file before it is sent to our servers. The passphrase itself is never uploaded. We only keep a session hint that you set one.

Titles and categories are encrypted the same way, so we cannot read labels either.

The algorithm

Key derivation is PBKDF2-HMAC-SHA-256 with 250,000 iterations and a fresh 16-byte random salt per item. The cipher is AES-256-GCM with a fresh 12-byte random IV per item.

Those numbers are the ones in the shipping client. We are not claiming Argon2 or another KDF we do not use.

If you lose the passphrase

Files cannot be recovered. That is intentional: we do not keep a key escrow. Choose a passphrase you will remember and keep a copy of anything you cannot afford to lose, outside the vault.

What this is not

This is not a published independent cryptographic audit. It is not a password manager. It is not a VPN and does not hide your IP. A compromised browser or device can still see plaintext while the vault is unlocked.

We host ciphertext and file size. That is honest client-side encryption, not a claim that we know nothing about the stored blob.