00 / security
Don't trust us. Verify us.
In plain language: your files are encrypted on your device with keys derived from your password and held only by you. Hvelv's servers store encrypted blocks they cannot decrypt. There is no master key, no recovery backdoor, and no support tool that can open a vault. If you lose your password and your recovery kit, your files are unrecoverable — by anyone. That inconvenience is the evidence the system works as claimed.
What we see
| email address | for login and receipts |
| storage used, blob sizes, timestamps | for quotas and sync |
| billing status via Stripe | we never see card numbers |
| IP addresses in short-lived logs | for abuse prevention |
Not on that list, because it cannot be: file contents, filenames, folder structure, passwords, keys.
Threat model
protects against
- · A breach of our servers — attackers get ciphertext and no keys
- · Insiders — employees (currently: one) cannot read vault contents
- · Content demands — we can only produce encrypted blobs and account metadata
- · Provider scanning and AI training — structurally impossible, not policy
does not protect against
- · Malware or spyware on your own device — if your device is compromised, so are your files
- · A weak or reused password — your password is the root of your keys; treat it accordingly
- · People you share with — once someone can decrypt a file, what they do with it is out of scope
- · Traffic analysis — we (and any network observer) can see that you sync, when, and roughly how much
One more honest boundary: any web-delivered encryption app must ship you its code each visit, so a coerced or compromised server is a theoretical attack on targeted users. We mitigate with signed, versioned builds, a strict no-third-party-scripts policy, and — for the highest-assurance path — an open-source desktop app whose builds are reproducible. We state this because you already knew it, and vendors who pretend otherwise are telling you something.
The cryptography
- · key derivation: Argon2id, client-side, per-account salt
- · bulk encryption: AES-256-GCM, 4 MiB chunks, per-file random keys
- · key hierarchy: password → root key → KEK → vault keys → file keys
- · filenames & tree: encrypted manifest blobs, padded sizes
- · sharing & devices: X25519 / Ed25519, out-of-band verification
- · recovery: 24-word kit generated at signup, wraps your KEK
Boring, audited primitives on purpose. The full design document — key hierarchy, wire formats, test vectors — is published for review with the open-source client at github.com/hvelvhq.
Audit commitment
An independent security audit by a recognized firm (Cure53-class) will be commissioned when Hvelv reaches $5,000 in monthly recurring revenue or 12 months after public launch — whichever comes first — and the report will be published here in full, unedited. This commitment is dated and funded; we'd rather show you the receipt than a badge.
Infrastructure
Encrypted blocks live in Cloudflare R2 object storage; the API runs on Cloudflare Workers; account metadata lives in a Postgres database. Payments are processed by Stripe on a separate origin — card details never touch Hvelv. This site sets no cookies, loads no third-party scripts, and runs no analytics beyond Cloudflare's cookie-free counters.
found something? security@hvelv.io — coordinated disclosure welcomed, credited, and answered by a human.