Source code and details: https://github.com/umutcamliyurt/Lethean

Lethean is a zero-knowledge encrypted storage app with no accounts, no email. Your passphrase is the only credential and never leaves the browser. Upload photos and videos, browse them in a gallery, and play them fully decrypted in memory, the server only ever sees ciphertext.

Features

• No user account required
• AES-256-GCM for client-side encryption
• Ciphertext padding to hide file size metadata
• Argon2id for key derivation
• Duress code for wiping the vault under coercion

Access tokens

Browsing a vault requires only its vaultId. Uploading additionally requires an operator-issued access token (10 GB quota by default), provisioned server-side.

A freshly issued token binds permanently to the first vault that uploads with it; a bound token cannot be reassigned.