Encrypted by default. Yours by design.
Every photo, file and document is end-to-end encrypted on your device, and runs on a server you control.
End-to-end encrypted
Every photo, file and document, along with its thumbnails, filenames and metadata, is encrypted on your device with libsodium before it leaves. The server only ever stores ciphertext.
Zero-knowledge
Your master key is derived from your password and never touches the server. Content keys are wrapped to it, so no one but you can decrypt your library: not a host, not us, not an attacker with the database.
Self-hosted, your keys
PolarHQ runs on hardware you own, with no third-party cloud, no telemetry and no lock-in. Your keys, your server, your data, exportable at any time.
How the encryption works
Your key never leaves your device
Your password derives a master key in your browser via a memory-hard KDF. The server stores only a verifier, never your key or password.
Every item gets its own key
Each photo, file and doc is encrypted with a unique random content key, which is then sealed to your master key and stored wrapped. Sharing hands over only that one item's key.
The server only serves ciphertext
Media is delivered through authenticated, ownership-checked routes (never public presigned links) and decrypted only in your app. Thumbnails, EXIF, locations and derivatives are encrypted too.
The tradeoff of real end-to-end encryption: without your password or recovery code, no one (including us) can recover encrypted data. Keep your recovery code safe.
Frequently asked questions
No. Every photo, file and document is encrypted on your device before upload, with a key derived from your password. The server only ever stores ciphertext and never has your key, so it can't read your library or even the file names, including if the database or storage is breached.