Four steps. Every step in your browser.
How it works
Every step happens on your device before a single byte reaches our servers. The RESQD API is zero-knowledge by architecture — not by promise.
Sign up with a passkey
Your fingerprint, Face ID, or Windows Hello creates a cryptographic identity bound to this device. Your vault key is derived from it via the WebAuthn PRF extension and never leaves the browser.
Drop a file
The browser generates a fresh per-file key, encrypts your file with XChaCha20-Poly1305, seals that key under your master key, and Reed-Solomon codes the ciphertext into 6 shards.
Six clouds, one vault
Each shard goes directly to a different storage backend via a presigned URL — RESQD's API never touches the bytes. No single cloud, or subpoena, can reconstruct your data. Any 4 of 6 shards is enough to recover.
Anchored on-chain
Every access rotates a canary commitment and writes it to Base L2. You can verify the read history cryptographically, forever, for less than a penny per access. If anyone — including us — reads a file without your knowledge, the on-chain sequence proves it.
For the specific cryptographic primitives and trust boundaries, read the Security Model.
Create your vault — free